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Line 15: {{trans\|Julia}} This runs in only 37 seconds which is surprisingly quick compared to Julia. However, I've just noticed that I'm using an out of date version of Julia (1.0.4) so hopefully the latest version will be able to close the gap. <~~lang~~syntaxhighlight lang="go">package main import ( Line 467: fmt.Println("The route taking the least time found was:\n", tp.path, "\nwhich has duration", int(tp.duration/60), "hours,", int(math.Round(math.Mod(tp.duration, 60))), "minutes.") }</~~lang~~syntaxhighlight> {{out}} Line 478: =={{header\|Julia}}== Brute force optimization search, practical for shorter path lengths, but would require a better algorithm for paths over twice this size. <~~lang~~syntaxhighlight lang="julia">module SailingPolars using DelimitedFiles Line 861: println("The route taking the least time found was:\n ", tp.path, "\nwhich has duration $(div(tp.duration, 60)) hours, $(rem(tp.duration, 60)) minutes.") </syntaxhighlight> ~~</lang>~~ The polar CSV file used for this solution, named polar.csv, is as follows. Note that this is a very detailed polar, chosen to stress the testing of the code. Most polar files are far smaller, Line 921: The Go version runs in about 44 seconds on my computer. This Nim version, compiled in release mode (which includes runtime checks), runs in 22 seconds (18 seconds if link time optimization is activated). When compiled without checks (“danger” mode), it runs in 15.5 seconds. <~~lang~~syntaxhighlight ~~Nim~~lang="nim">import hashes, math, parsecsv, sequtils, sets, strutils, sugar type Line 1,237: echo "The route taking the least time found was:" echo tp.path echo "which has duration ", int(tp.duration / 60), " hours ", toInt(tp.duration mod 60), " minutes."</~~lang~~syntaxhighlight> {{out}} Line 1,245: =={{header\|Phix}}== {{trans\|Go}} ~~<lang Phix>-- demo/rosetta/Weather_Routing.exw~~ <!--<syntaxhighlight lang="phix">(phixonline)--> ~~function to_numbers(sequence s)~~ <span style="color: #000080;font-style:italic;">-- ~~for i=1 to length(s) do~~ -- demo\rosetta\Weather_Routing.exw ~~s[i] = to_number(s[i])~~ -- ================================ ~~end for~~ --</span> ~~return s~~ <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span> ~~end function~~ <span style="color: #008080;">constant</span> <span style="color: #000000;">polar_csv</span> <span style="color: #0000FF;">=</span> <span style="font-size: 75%; color: #008000;">""" TWA\TWS;0;4;5;6;7;8;9;10;11;12;13;14;15;16;17;18;19;20;21;22;23;24;25;26;27;28;29;30;35;40;60;70 ~~function getpolardata(string s)~~ 40;0;0.53;0.54;0.49;0.4;0.31;0.21;0.16;0.11;0.08;0.05;0.03;0.02;0.01;0;0;0;0;0;0;0;0;0;0;0;0;0;0;-0.01;-0.05;-0.1;-0.11 -- 41;0;0.61;0.62;0.56;0.47;0.36;0.25;0.19;0.14;0.1;0.07;0.04;0.02;0.01;0.01;0;0;0;0;0;0;0;0;0;0;0;0;0;0;-0.04;-0.09;-0.1 ~~-- A sailing polar file is a CSV file, with ';' used as the comma separator instead of a comma.~~ 44;0;0.89;0.91;0.82;0.69;0.56;0.42;0.33;0.24;0.18;0.13;0.08;0.05;0.03;0.02;0.01;0.01;0;0;0;0;0;0;0;0;0;0;0;0;-0.02;-0.06;-0.06 ~~-- The first line of the file contains labels for the wind velocities that make up columns, and~~ 45;0;0.99;1.02;0.92;0.78;0.64;0.49;0.39;0.29;0.22;0.15;0.1;0.07;0.04;0.02;0.01;0.01;0;0;0;0;0;0;0;0;0;0;0;0;-0.01;-0.05;-0.05 ~~-- the first entry of each row makes up a column of angle of sailing direction from wind in degrees~~ 46;0;1.11;1.14;1.02;0.87;0.73;0.57;0.45;0.35;0.26;0.18;0.13;0.08;0.05;0.03;0.02;0.01;0.01;0;0;0;0;0;0;0;0;0;0;0;-0.01;-0.04;-0.05 -- 47;0;1.23;1.25;1.14;0.97;0.82;0.66;0.53;0.41;0.31;0.22;0.15;0.1;0.07;0.04;0.02;0.02;0.01;0.01;0;0;0;0;0;0;0;0;0;0;-0.01;-0.03;-0.04 ~~sequence lines = split_any(s,"\r\n"),~~ 48;0;1.37;1.37;1.26;1.08;0.93;0.76;0.61;0.48;0.36;0.26;0.19;0.13;0.08;0.05;0.03;0.02;0.01;0.01;0.01;0;0;0;0;0;0;0;0;0;0;-0.02;-0.03 ~~winds = to_numbers(split(lines[1],";")[2..$]),~~ 49;0;1.5;1.5;1.39;1.2;1.05;0.87;0.71;0.56;0.42;0.31;0.22;0.15;0.1;0.07;0.04;0.03;0.02;0.01;0.01;0;0;0;0;0;0;0;0;0;0;-0.02;-0.02 ~~degrees = {}, speeds = {}~~ 50;0;1.65;1.64;1.52;1.33;1.18;1;0.81;0.65;0.49;0.37;0.26;0.19;0.13;0.08;0.05;0.04;0.03;0.02;0.01;0.01;0;0;0;0;0;0;0;0;0;-0.01;-0.02 ~~for i=2 to length(lines) do~~ 51;0;1.79;1.77;1.67;1.46;1.32;1.13;0.92;0.74;0.57;0.43;0.31;0.22;0.15;0.1;0.07;0.05;0.03;0.02;0.02;0.01;0.01;0;0;0;0;0;0;0;0;-0.01;-0.02 ~~sequence l = to_numbers(split(lines[i],";"))~~ 53;0;2.1;2.07;1.99;1.76;1.62;1.4;1.14;0.95;0.74;0.57;0.43;0.31;0.22;0.16;0.1;0.08;0.06;0.04;0.03;0.02;0.01;0.01;0.01;0;0;0;0;0;0;-0.01;-0.01 ~~if length(l)!=length(winds)+1 then ?9/0 end if~~ 54;0;2.26;2.22;2.16;1.92;1.78;1.55;1.28;1.06;0.84;0.65;0.5;0.37;0.27;0.19;0.13;0.1;0.07;0.06;0.04;0.03;0.02;0.01;0.01;0;0;0;0;0;0;0;-0.01 ~~degrees = append(degrees,l[1])~~ 55;0;2.43;2.39;2.34;2.09;1.95;1.7;1.42;1.18;0.95;0.74;0.57;0.43;0.32;0.23;0.16;0.12;0.09;0.07;0.05;0.04;0.03;0.02;0.01;0.01;0;0;0;0;0;0;-0.01 ~~speeds = append(speeds,l[2..$])~~ 60;0;3.29;3.33;3.33;3.08;2.93;2.64;2.29;1.98;1.66;1.36;1.1;0.88;0.68;0.53;0.39;0.32;0.26;0.21;0.17;0.13;0.1;0.07;0.05;0.04;0.03;0.02;0.01;0;0;0;0 ~~end for~~ 70;0;5.2;5.53;5.74;5.59;5.5;5.22;4.84;4.46;3.94;3.51;3.08;2.65;2.26;1.9;1.55;1.38;1.22;1.06;0.92;0.78;0.66;0.55;0.46;0.37;0.3;0.24;0.18;0.03;0;0;0 ~~return {winds, degrees, speeds}~~ 80;0;6.8;7.43;7.97;8.02;8.23;8.34;8.2;7.9;7.37;6.91;6.43;5.9;5.32;4.72;4.12;3.83;3.55;3.25;2.96;2.67;2.4;2.13;1.88;1.65;1.43;1.22;1.04;0.37;0.09;0.01;0 ~~end function~~ 90;0;7.59;8.5;9.4;9.73;10.4;11.16;11.53;11.56;11.3;11.05;10.77;10.44;9.83;9.07;8.34;8;7.65;7.27;6.88;6.46;6.04;5.61;5.15;4.74;4.33;3.88;3.51;1.72;0.67;0.12;0.03 100;0;7.34;8.25;9.16;9.86;10.5;11.95;12.79;13.5;14.02;14.4;14.37;14.5;14.4;13.92;13.52;13.19;12.79;12.51;12.1;11.66;11.22;10.77;10.26;9.72;9.2;8.58;8.01;4.87;2.51;0.7;0.23 -- 110;0;7.09;7.97;8.84;9.74;10.09;11.85;12.75;13.84;14.99;16.02;16.33;17.1;17.83;17.99;18.32;18.14;17.81;17.84;17.6;17.3;17.05;16.83;16.53;16.03;15.59;15.03;14.37;10.26;6.41;2.32;0.86 ~~-- winds is a list of wind speeds~~ 120;0;6.59;7.42;8.3;9.1;9.56;10.83;11.6;13.1;13.87;14.66;15.75;16.67;17.63;18.43;19.62;20.17;20.6;21.12;21.55;21.75;21.91;22.07;21.9;21.58;21.29;20.92;20.29;16.47;12.03;5.49;2.26 ~~-- degrees is a list of angles in degrees of direction relative to the wind~~ 129;0;6.14;6.93;7.83;8.52;9.09;9.89;10.57;12.42;12.87;13.43;15.23;16.16;17.08;18.07;19.48;20.35;21.22;21.93;22.85;23.44;23.98;24.55;24.59;24.55;24.51;24.46;24;21.56;17.75;9.64;4.25 ~~-- (note 0 degrees is directly into the wind, 180 degrees is directly downwind)~~ 130;0;6.07;6.87;7.76;8.44;9.02;9.8;10.48;12.29;12.73;13.27;15.08;16.03;16.97;17.96;19.36;20.25;21.15;21.88;22.82;23.44;24.03;24.6;24.66;24.68;24.67;24.64;24.24;22;18.33;10.11;4.5 ~~-- each speeds[i] is an array of length(winds) for each degrees[i]~~ 135;0;5.72;6.57;7.36;8.02;8.65;9.38;10.11;11.52;11.97;12.55;13.85;15.31;16.31;17.33;18.54;19.48;20.35;21.28;22.3;23.08;24.09;24.63;24.69;24.78;24.79;24.91;24.82;23.74;20.98;12.39;5.78 -- 136;0;5.66;6.5;7.28;7.93;8.57;9.3;10.04;11.34;11.82;12.42;13.62;15.06;16.17;17.2;18.35;19.29;20.15;21.12;22.15;22.96;24.07;24.6;24.67;24.76;24.75;24.85;24.81;23.98;21.45;12.8;6.03 ~~constant {winds, degrees, speeds} = getpolardata(get_text("polar.csv"))~~ 139;0;5.42;6.31;6.92;7.67;8.34;9.08;9.86;10.86;11.32;12.03;12.99;14.3;15.73;16.76;17.76;18.71;19.53;20.6;21.66;22.54;23.92;24.44;24.53;24.64;24.58;24.65;24.67;24.47;22.68;13.79;6.73 ~~-- (note the distributed version uses a literal string constant instead)~~ 140;0;5.35;6.22;6.79;7.59;8.26;9;9.8;10.72;11.16;11.89;12.79;14.06;15.5;16.62;17.57;18.51;19.32;20.43;21.49;22.4;23.84;24.36;24.46;24.58;24.51;24.57;24.61;24.56;23.02;14.08;6.96 ~~constant R = 6372800 -- Earth's approximate radius in meters~~ 141;0;5.29;6.12;6.67;7.48;8.18;8.93;9.74;10.57;11.02;11.77;12.62;13.82;15.26;16.47;17.38;18.32;19.04;20.28;21.31;22.07;23.53;24;24.21;24.29;24.43;24.48;24.55;24.61;23.33;14.31;7.18 ~~constant timeinterval = 10 -- the minutes duration for each TimeSlice~~ 142;0;5.23;6.02;6.57;7.39;8.1;8.86;9.67;10.43;10.88;11.64;12.45;13.59;15.03;16.24;17.14;18.06;18.77;19.98;21.01;21.75;23.18;23.65;23.86;23.95;24.34;24.39;24.48;24.61;23.61;14.54;7.4 143;0;5.16;5.93;6.45;7.3;8;8.78;9.54;10.27;10.75;11.5;12.28;13.36;14.8;16.01;16.9;17.81;18.5;19.69;20.72;21.43;22.84;23.31;23.52;23.61;24.05;24.27;24.41;24.57;23.85;14.8;7.6 ~~function deg2rad(atom deg) return remainder(degPI/180+2PI,2PI) end function~~ 144;0;5.09;5.83;6.33;7.23;7.92;8.66;9.41;10.13;10.62;11.39;12.13;13.13;14.57;15.78;16.65;17.56;18.24;19.41;20.43;21.12;22.5;22.97;23.19;23.28;23.73;24.08;24.33;24.49;24.04;15;7.8 ~~function rad2deg(atom rad) return remainder (rad(180/PI)+360,360) end function~~ 145;0;5.02;5.73;6.23;7.15;7.85;8.55;9.28;9.98;10.51;11.27;11.98;12.92;14.35;15.56;16.42;17.31;17.97;19.13;20.14;20.82;22.17;22.64;22.87;22.96;23.42;23.81;24.23;24.41;24.19;15.14;7.98 ~~function sind(atom deg) return sin(deg2rad(deg)) end function~~ 146;0;4.96;5.64;6.12;7.07;7.77;8.43;9.15;9.84;10.38;11.16;11.83;12.71;14.12;15.35;16.19;17.07;17.72;18.86;19.86;20.51;21.84;22.31;22.56;22.65;23.12;23.48;23.94;24.33;24.3;15.3;8.16 ~~function cosd(atom deg) return cos(deg2rad(deg)) end function~~ 148;0;4.82;5.45;5.91;6.9;7.59;8.21;8.89;9.55;10.14;10.89;11.55;12.29;13.7;14.92;15.74;16.6;17.23;18.32;19.3;19.91;21.2;21.67;21.95;22.05;22.53;22.87;23.38;24.13;24.39;15.52;8.46 ~~function asind(atom deg) return rad2deg(arcsin(deg)) end function~~ 149;0;4.76;5.35;5.81;6.78;7.49;8.09;8.78;9.42;10.01;10.76;11.41;12.1;13.48;14.71;15.52;16.36;16.98;18.06;19.03;19.63;20.89;21.37;21.67;21.77;22.26;22.61;23.12;23.98;24.37;15.57;8.58 ~~function atand(atom x,y) return rad2deg(atan2(x,y)) end function~~ 150;0;4.69;5.26;5.7;6.67;7.37;7.96;8.64;9.26;9.86;10.6;11.24;11.89;13.26;14.48;15.29;16.11;16.73;17.79;18.74;19.33;20.55;21.04;21.37;21.48;21.98;22.34;22.83;23.69;24.11;15.6;8.67 155;0;4.33;4.74;5.16;6.16;6.79;7.33;7.96;8.51;9.15;9.81;10.4;10.85;12.14;13.37;14.1;14.87;15.48;16.42;17.3;17.8;18.88;19.39;19.86;20;20.54;20.97;21.45;22.25;22.77;15.38;8.89 ~~function haversine(atom lat1, lon1, lat2, lon2)~~ 160;0;4.09;4.41;4.83;5.77;6.39;6.94;7.55;8.04;8.67;9.28;9.83;10.24;11.46;12.69;13.39;14.11;14.73;15.6;16.41;16.87;17.85;18.4;18.97;19.15;19.72;20.2;20.65;21.35;21.84;14.95;8.74 -- 162;0;4;4.29;4.69;5.62;6.23;6.77;7.38;7.86;8.48;9.07;9.6;10;11.18;12.42;13.1;13.81;14.43;15.27;16.06;16.5;17.43;18;18.62;18.81;19.39;19.89;20.33;20.99;21.48;14.76;8.61 ~~-- Calculate the haversine function for two points on the Earth's surface.~~ 168;0;3.74;3.93;4.35;5.15;5.75;6.31;6.93;7.34;7.92;8.45;8.95;9.35;10.44;11.68;12.32;12.99;13.63;14.39;15.11;15.5;16.31;16.94;17.7;17.92;18.53;19.08;19.49;19.99;20.46;14.34;8.3 -- 170;0;3.69;3.85;4.27;5.04;5.65;6.22;6.82;7.23;7.8;8.31;8.8;9.22;10.27;11.51;12.15;12.81;13.45;14.19;14.9;15.28;16.06;16.7;17.51;17.73;18.34;18.91;19.31;19.77;20.22;14.24;8.24 ~~-- Given two latitude, longitude pairs in degrees for a point on the Earth,~~ 174;0;3.57;3.69;4.11;4.83;5.43;6.01;6.62;7;7.55;8.03;8.5;8.93;9.95;11.19;11.81;12.45;13.11;13.81;14.48;14.84;15.57;16.24;17.11;17.35;17.98;18.57;18.95;19.33;19.77;14.03;8.13 ~~-- get distance in meters and the initial direction of travel in degrees for~~ 180;0;3.51;3.6;4.03;4.71;5.31;5.91;6.51;6.88;7.41;7.88;8.33;8.79;9.78;11.02;11.63;12.26;12.93;13.61;14.26;14.61;15.31;15.99;16.9;17.15;17.79;18.39;18.77;19.09;19.52;13.87;8.07 ~~-- movement from point 1 to point 2.~~ """</span> -- ~~atom dlat = lat2 - lat1,~~ ~~dlon = lon2 - lon1,~~ ~~a = power(sind(dlat/2),2) + cosd(lat1)cosd(lat2)power(sind(dlon/2),2),~~ ~~c = 2.0 * asind(sqrt(a)),~~ ~~theta = atand(sind(dlon)cosd(lat2),~~ ~~cosd(lat1)sind(lat2) - sind(lat1)cosd(lat2)cosd(dlon))~~ ~~theta = remainder(theta+360, 360)~~ ~~return {Rc0.5399565, theta}~~ ~~end function~~ ~~function find_range(atom v, sequence s)~~ ~~-- Returns the indexes of s of the first >=v, and the last <=v~~ ~~for i=1 to length(s) do~~ ~~if s[i]>=v then~~ ~~for j=length(s) to 1 by -1 do~~ ~~if s[j]<=v then return {i,j} end if~~ ~~end for~~ ~~exit~~ ~~end if~~ ~~end for~~ ~~return {-1,-1}~~ ~~end function~~ ~~function boatspeed(atom pointofsail, windspeed)~~ -- ~~-- Calculate the expected sailing speed in a specified direction in knots,~~ ~~-- given a desired point of sail in degrees, and wind speed in knots (for~~ ~~-- the previously loaded sailing polar data)~~ -- ~~integer {ld,ud} = find_range(pointofsail, degrees),~~ ~~{lv,uv} = find_range(windspeed, winds)~~ ~~if find(-1,{ld, ud, lv, uv}) then return -1 end if~~ ~~atom wu = winds[uv],~~ ~~wl = winds[lv],~~ ~~du = degrees[ud],~~ ~~dl = degrees[ld],~~ f ~~if ld==ud then~~ ~~f = iff(uv==lv ? 1 :~~ ~~(wu-windspeed)/(wu-wl))~~ ~~elsif uv==lv then~~ ~~f = (du-pointofsail)/(du-dl)~~ ~~else~~ ~~f = ((du-pointofsail)/(du-dl)+~~ ~~(wu-windspeed)/(wu-wl))/2~~ ~~end if~~ ~~atom su = speeds[ud,uv],~~ ~~sl = speeds[ld,lv],~~ ~~res = su - f(su-sl)~~ ~~return res~~ ~~end function~~ ~~function sailingspeed(atom azimuth, pointofsail, ws)~~ -- ~~-- Calculate the expected net boat speed in a desired direction versus the wind (azimuth).~~ ~~-- This is generally different from the actual boat speed in its actual direction.~~ ~~-- Directions are in degrees (pointofsail is the ship direction from wind),~~ ~~-- and velocity of wind (ws) is in knots.~~ -- ~~return boatspeed(pointofsail, ws) cosd(abs(pointofsail-azimuth))~~ ~~end function~~ ~~struct SurfaceParameters~~ -- ~~-- wind and surface current, direction and velocity, for a given position~~ ~~-- directions are in degrees from north, and velocities are in knots.~~ -- ~~public atom winddirection,~~ ~~windvelocity,~~ ~~currentdirection,~~ ~~currentvelocity~~ ~~end struct~~ ~~function bestvectorspeed(atom dirtravel, SurfaceParameters p)~~ -- ~~-- Calculate the net direction and velocity of a sailing ship.~~ -- ~~atom wd = p.winddirection,~~ ~~wv = p.windvelocity,~~ ~~cd = p.currentdirection,~~ ~~cv = p.currentvelocity,~~ ~~azimuth = remainder(dirtravel-wd,360)~~ ~~if azimuth<0 then azimuth += 360 end if~~ ~~if azimuth>180 then azimuth = 360-azimuth end if~~ ~~atom vmg = boatspeed(azimuth, wv),~~ ~~other = -1~~ ~~integer idx = -1~~ ~~for i=1 to length(degrees) do~~ ~~atom ss = sailingspeed(azimuth, degrees[i], wv)~~ ~~if ss>other then {other,idx} = {ss,i} end if~~ ~~end for~~ ~~if other>vmg then~~ ~~azimuth = degrees[idx]~~ ~~vmg = other~~ ~~end if~~ ~~atom dirchosen = deg2rad(wd + azimuth),~~ ~~dircurrent = deg2rad(cd),~~ ~~wx = vmg * sin(dirchosen),~~ ~~wy = vmg * cos(dirchosen),~~ ~~curx = cv * sin(dircurrent),~~ ~~cury = cv * cos(dircurrent)~~ ~~return sqrt(power(wx+curx,2) + power(wy+cury,2))~~ ~~end function~~ ~~function sailsegmenttime(SurfaceParameters p, atom lat1, lon1, lat2, lon2)~~ -- ~~-- Calculate the trip time in minutes from (lat1, lon1) to the destination (lat2, lon2).~~ ~~-- Uses the data in SurfaceParameters p for wind and current velocity and direction.~~ -- ~~atom {distance, direction} = haversine(lat1, lon1, lat2, lon2),~~ ~~velocity = bestvectorspeed(direction, p)~~ ~~-- minutes/s * m / (knots * (m/s / knot)) = minutes~~ ~~atom res = (1/60) * distance / (velocity * 1.94384)~~ ~~return res~~ ~~end function~~ -- ~~-- The data is selected so the best time path is slightly longer than the~~ ~~-- shortest length path. The forbidden regions are x, representing land or reef.~~ ~~-- The allowed sailing points are . and start and finish are S and F.~~ -- ~~constant chart = split("""~~ ~~...S.....~~ ~~x......x.~~ ~~....x..x.~~ ~~x...xx.x.~~ ~~x...xx.x.~~ ~~..xxxx.xx~~ ~~x..xxx...~~ ~~.......xx~~ ~~x..F..x.x""",'\n')~~ ~~function minimum_time_route(sequence timeframe, start, finish)~~ -- ~~-- Get the fastest route from start to finish for some detailed sea/ship parameters.~~ ~~-- timeframe is a massive 200 * 9x9 * {pt,SurfaceParameters}~~ ~~-- note that polar data (ie winds, degrees, speeds) is static here, for simplicity.~~ -- ~~atom t0 = time(),~~ ~~mintime = 1000.0~~ ~~integer xmax = length(chart[1]),~~ ~~ymax = length(chart),~~ ~~{py,px} = start~~ ~~sequence todo = {start},~~ ~~costs = repeat(repeat(-1,xmax),ymax), -- (lowest durations)~~ ~~paths = repeat(repeat(0,xmax),ymax), -- (single backlinks)~~ ~~minpath = {}~~ ~~costs[py,px] = 0~~ ~~while length(todo) do~~ ~~{py,px} = todo[1]~~ ~~todo = todo[2..$]~~ ~~atom duration = costs[py,px]~~ ~~integer sdx = remainder(floor(round(duration)/timeinterval),length(timeframe))+1~~ ~~sequence s = timeframe[sdx]~~ ~~for nx=px-1 to px+1 do~~ ~~for ny=py-1 to py+1 do~~ ~~if (nx!=px or ny!=py)~~ ~~and nx>=1 and nx<=xmax~~ ~~and ny>=1 and ny<=ymax~~ ~~and chart[ny,nx]!='x' then~~ ~~sequence gp1 = s[py,px], -- {pt,SurfaceParameters}~~ ~~gp2 = s[ny,nx] -- ""~~ ~~atom {lat1, lon1} = gp1[1],~~ ~~{lat2, lon2} = gp2[1]~~ ~~SurfaceParameters sp = gp1[2]~~ ~~atom nt = duration + sailsegmenttime(sp, lat1, lon1, lat2, lon2)~~ ~~if costs[ny,nx]=-1 or nt<costs[ny,nx] then~~ ~~-- a larger (than 9x9) simulation might benefit from not~~ ~~-- putting any already-too-long routes back on the todo~~ ~~-- list and/or processing todo lowest duration first.~~ ~~costs[ny,nx] = nt~~ ~~paths[ny,nx] = {py,px}~~ ~~if not find({ny,nx},todo) then~~ ~~todo = append(todo,{ny,nx})~~ ~~end if~~ ~~elsif nt==costs[ny,nx] then~~ ~~-- (Should multiple same-time routes exist, we could store~~ ~~-- multiple back-links and whip up a simple [recursive]~~ ~~-- routine to rebuild them all. Or just ignore them.)~~ ~~?9/0~~ ~~end if~~ ~~end if~~ ~~end for~~ ~~end for~~ ~~s = {} -- (simplify debugging)~~ ~~end while~~ ~~timeframe = {} -- (simplify debugging)~~ ~~{py,px} = finish~~ ~~mintime = costs[py,px]~~ ~~minpath = {finish}~~ ~~while true do~~ ~~object pyx = paths[py,px]~~ ~~if pyx=0 then exit end if~~ ~~minpath = prepend(minpath,pyx)~~ ~~paths[py,px] = 0 -- (be safe, why not)~~ ~~{py,px} = pyx~~ ~~end while~~ ~~if minpath[1]!=start then ?9/0 end if~~ ~~return {minpath,elapsed(mintime60),elapsed(time()-t0)}~~ ~~end function~~ <span style="color: #008080;">function</span> <span style="color: #000000;">to_numbers</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> ~~function surfacebylongitude(atom lon)~~ <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> ~~-- Create regional wind patterns on the map.~~ <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">to_number</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">])</span> ~~sequence p = iff(lon < -155.03 ? { -5.0, 8, 150, 0.5} :~~ <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> ~~iff(lon < -155.99 ? {-90.0, 20, 150, 0.4} :~~ <span style="color: #008080;">return</span> <span style="color: #000000;">s</span> ~~{180.0, 25, 150, 0.3}))~~ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> ~~SurfaceParameters res = new(p)~~ ~~return res~~ <span style="color: #008080;">function</span> <span style="color: #000000;">getpolardata</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> ~~end function~~ <span style="color: #000080;font-style:italic;">-- -- A sailing polar file is a CSV file, with ';' used as the comma separator instead of a comma. ~~procedure mutatetimeslices(sequence slices)~~ -- The first line of the file contains labels for the wind velocities that make up columns, and ~~-- Vary wind speeds over time.~~ -- the first entry of each row makes up a column of angle of sailing direction from wind in degrees ~~for i=1 to length(slices) do~~ --</span> ~~sequence s = slices[i]~~ <span style="color: #004080;">sequence</span> <span style="color: #000000;">lines</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">split_any</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\r\n"</span><span style="color: #0000FF;">),</span> ~~for j=1 to length(s) do~~ <span style="color: #000000;">winds</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">to_numbers</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lines</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">],</span><span style="color: #008000;">";"</span><span style="color: #0000FF;">)[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..$]),</span> ~~sequence sj = s[j]~~ <span style="color: #000000;">degrees</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{},</span> <span style="color: #000000;">speeds</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span> ~~for k=1 to length(sj) do~~ <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lines</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> ~~SurfaceParameters p = sj[k][2]~~ <span style="color: #004080;">sequence</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">to_numbers</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lines</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span><span style="color: #008000;">";"</span><span style="color: #0000FF;">))</span> ~~p.windvelocity = p.windvelocity (1+0.002i)~~ <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">l</span><span style="color: #0000FF;">)!=</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">winds</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> ~~end for~~ <span style="color: #000000;">degrees</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">degrees</span><span style="color: #0000FF;">,</span><span style="color: #000000;">l</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">])</span> ~~end for~~ <span style="color: #000000;">speeds</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">speeds</span><span style="color: #0000FF;">,</span><span style="color: #000000;">l</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..$])</span> ~~end for~~ <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> ~~end procedure~~ <span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">winds</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">degrees</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">speeds</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #000080;font-style:italic;">-- ~~sequence slices = repeat(null,200)~~ -- winds is a list of wind speeds ~~for s=1 to length(slices) do~~ -- degrees is a list of angles in degrees of direction relative to the wind ~~sequence gpoints = repeat(null,9)~~ -- (note 0 degrees is directly into the wind, 180 degrees is directly downwind) ~~for i=1 to 9 do~~ -- each speeds[i] is an array of length(winds) for each degrees[i] ~~atom lat = 19.78 - 2/60 + i/60~~ --</span> ~~gpoints[i] = repeat(null,9)~~ <span style="color: #008080;">constant</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">winds</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">degrees</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">speeds</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">getpolardata</span><span style="color: #0000FF;">(</span><span style="color: #000000;">polar_csv</span><span style="color: #0000FF;">)</span> ~~for j=1 to 9 do~~ <span style="color: #000080;font-style:italic;">--constant {winds, degrees, speeds} = getpolardata(get_text("polar.csv")) -- alt</span> ~~atom lon = -155.0 - 6/60 + j/60~~ <span style="color: #008080;">constant</span> <span style="color: #000000;">R</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">6372800</span> <span style="color: #000080;font-style:italic;">-- Earth's approximate radius in meters</span> ~~gpoints[i][j] = {{lat,lon}, surfacebylongitude(lon)}~~ <span style="color: #008080;">constant</span> <span style="color: #000000;">timeinterval</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">10</span> <span style="color: #000080;font-style:italic;">-- the minutes duration for each TimeSlice</span> ~~end for~~ ~~end for~~ <span style="color: #008080;">function</span> <span style="color: #000000;">deg2rad</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">deg</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">deg</span><span style="color: #0000FF;"></span><span style="color: #004600;">PI</span><span style="color: #0000FF;">/</span><span style="color: #000000;">180</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;"></span><span style="color: #004600;">PI</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;"></span><span style="color: #004600;">PI</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> ~~slices[s] = gpoints~~ <span style="color: #008080;">function</span> <span style="color: #000000;">rad2deg</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">rad</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">remainder</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">rad</span><span style="color: #0000FF;">(</span><span style="color: #000000;">180</span><span style="color: #0000FF;">/</span><span style="color: #004600;">PI</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">360</span><span style="color: #0000FF;">,</span><span style="color: #000000;">360</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> ~~end for~~ <span style="color: #008080;">function</span> <span style="color: #000000;">sind</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">deg</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">sin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">deg2rad</span><span style="color: #0000FF;">(</span><span style="color: #000000;">deg</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> ~~mutatetimeslices(slices)~~ <span style="color: #008080;">function</span> <span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">deg</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">cos</span><span style="color: #0000FF;">(</span><span style="color: #000000;">deg2rad</span><span style="color: #0000FF;">(</span><span style="color: #000000;">deg</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> ~~constant fmt = """~~ <span style="color: #008080;">function</span> <span style="color: #000000;">asind</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">deg</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #000000;">rad2deg</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">arcsin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">deg</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> ~~The route taking the least time found was:~~ <span style="color: #008080;">function</span> <span style="color: #000000;">atand</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #000000;">rad2deg</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">atan2</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> %v ~~which has duration %s [route found in %s]~~ <span style="color: #008080;">function</span> <span style="color: #000000;">haversine</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">lat1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lat2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon2</span><span style="color: #0000FF;">)</span> ~~"""~~ <span style="color: #000080;font-style:italic;">-- ~~printf(1,fmt,minimum_time_route(slices,{1,4},{9,4}))</lang>~~ -- Calculate the haversine function for two points on the Earth's surface. -- -- Given two latitude, longitude pairs in degrees for a point on the Earth, -- get distance in meters and the initial direction of travel in degrees for -- movement from point 1 to point 2. --</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">dlat</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">lat2</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">lat1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">dlon</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">lon2</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">lon1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">a</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlat</span><span style="color: #0000FF;">/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">),</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat1</span><span style="color: #0000FF;">)</span><span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat2</span><span style="color: #0000FF;">)</span><span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlon</span><span style="color: #0000FF;">/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">),</span><span style="color: #000000;">2</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">c</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2.0</span> <span style="color: #0000FF;"></span> <span style="color: #000000;">asind</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">sqrt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">)),</span> <span style="color: #000000;">theta</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">atand</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlon</span><span style="color: #0000FF;">)</span><span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat2</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat1</span><span style="color: #0000FF;">)</span><span style="color: #000000;">sind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat2</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">sind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat1</span><span style="color: #0000FF;">)</span><span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat2</span><span style="color: #0000FF;">)</span><span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlon</span><span style="color: #0000FF;">))</span> <span style="color: #000000;">theta</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">theta</span><span style="color: #0000FF;">+</span><span style="color: #000000;">360</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">360</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">R</span><span style="color: #0000FF;"></span><span style="color: #000000;">c</span><span style="color: #0000FF;"></span><span style="color: #000000;">0.5399565</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">theta</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #008080;">function</span> <span style="color: #000000;">find_range</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">v</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- Returns the indexes of s of the first >=v, and the last <=v</span> <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> <span style="color: #008080;">if</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]>=</span><span style="color: #000000;">v</span> <span style="color: #008080;">then</span> <span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">to</span> <span style="color: #000000;">1</span> <span style="color: #008080;">by</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span> <span style="color: #008080;">if</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]<=</span><span style="color: #000000;">v</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">i</span><span style="color: #0000FF;">,</span><span style="color: #000000;">j</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #008080;">return</span> <span style="color: #0000FF;">{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #008080;">function</span> <span style="color: #000000;">boatspeed</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">pointofsail</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">windspeed</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- -- Calculate the expected sailing speed in a specified direction in knots, -- given a desired point of sail in degrees, and wind speed in knots (for -- the previously loaded sailing polar data) --</span> <span style="color: #004080;">integer</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">ld</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ud</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">find_range</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pointofsail</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">degrees</span><span style="color: #0000FF;">),</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">lv</span><span style="color: #0000FF;">,</span><span style="color: #000000;">uv</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">find_range</span><span style="color: #0000FF;">(</span><span style="color: #000000;">windspeed</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">winds</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">ld</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ud</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lv</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">uv</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">wu</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">winds</span><span style="color: #0000FF;">[</span><span style="color: #000000;">uv</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">wl</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">winds</span><span style="color: #0000FF;">[</span><span style="color: #000000;">lv</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">du</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">degrees</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ud</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">dl</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">degrees</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ld</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">f</span> <span style="color: #008080;">if</span> <span style="color: #000000;">ld</span><span style="color: #0000FF;">==</span><span style="color: #000000;">ud</span> <span style="color: #008080;">then</span> <span style="color: #000000;">f</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">uv</span><span style="color: #0000FF;">==</span><span style="color: #000000;">lv</span> <span style="color: #0000FF;">?</span> <span style="color: #000000;">1</span> <span style="color: #0000FF;">:</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">wu</span><span style="color: #0000FF;">-</span><span style="color: #000000;">windspeed</span><span style="color: #0000FF;">)/(</span><span style="color: #000000;">wu</span><span style="color: #0000FF;">-</span><span style="color: #000000;">wl</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">elsif</span> <span style="color: #000000;">uv</span><span style="color: #0000FF;">==</span><span style="color: #000000;">lv</span> <span style="color: #008080;">then</span> <span style="color: #000000;">f</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">du</span><span style="color: #0000FF;">-</span><span style="color: #000000;">pointofsail</span><span style="color: #0000FF;">)/(</span><span style="color: #000000;">du</span><span style="color: #0000FF;">-</span><span style="color: #000000;">dl</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">else</span> <span style="color: #000000;">f</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">((</span><span style="color: #000000;">du</span><span style="color: #0000FF;">-</span><span style="color: #000000;">pointofsail</span><span style="color: #0000FF;">)/(</span><span style="color: #000000;">du</span><span style="color: #0000FF;">-</span><span style="color: #000000;">dl</span><span style="color: #0000FF;">)+</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">wu</span><span style="color: #0000FF;">-</span><span style="color: #000000;">windspeed</span><span style="color: #0000FF;">)/(</span><span style="color: #000000;">wu</span><span style="color: #0000FF;">-</span><span style="color: #000000;">wl</span><span style="color: #0000FF;">))/</span><span style="color: #000000;">2</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">su</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">speeds</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ud</span><span style="color: #0000FF;">,</span><span style="color: #000000;">uv</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">sl</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">speeds</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ld</span><span style="color: #0000FF;">,</span><span style="color: #000000;">lv</span><span style="color: #0000FF;">],</span> <span style="color: #000080;font-style:italic;">-- res = su + f(sl-su) -- (original)</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">su</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">f</span><span style="color: #0000FF;">(</span><span style="color: #000000;">su</span><span style="color: #0000FF;">-</span><span style="color: #000000;">sl</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- (equivalent) -- res = sl + (1-f)(su-sl) -- (also equivalent)</span> <span style="color: #008080;">return</span> <span style="color: #000000;">res</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #008080;">function</span> <span style="color: #000000;">sailingspeed</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">azimuth</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">pointofsail</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ws</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- -- Calculate the expected net boat speed in a desired direction versus the wind (azimuth). -- This is generally different from the actual boat speed in its actual direction. -- Directions are in degrees (pointofsail is the ship direction from wind), -- and velocity of wind (ws) is in knots. --</span> <span style="color: #008080;">return</span> <span style="color: #000000;">boatspeed</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pointofsail</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ws</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;"></span> <span style="color: #000000;">cosd</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">abs</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pointofsail</span><span style="color: #0000FF;">-</span><span style="color: #000000;">azimuth</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #008080;">function</span> <span style="color: #000000;">bestvectorspeed</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">dirtravel</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">surfaceparameters</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- -- Calculate the net direction and velocity of a sailing ship. --</span> <span style="color: #004080;">atom</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">winddirection</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">windvelocity</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">currentdirection</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">currentvelocity</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">surfaceparameters</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">azimuth</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dirtravel</span><span style="color: #0000FF;">-</span><span style="color: #000000;">winddirection</span><span style="color: #0000FF;">,</span><span style="color: #000000;">360</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">if</span> <span style="color: #000000;">azimuth</span><span style="color: #0000FF;"><</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #000000;">azimuth</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">360</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">if</span> <span style="color: #000000;">azimuth</span><span style="color: #0000FF;">></span><span style="color: #000000;">180</span> <span style="color: #008080;">then</span> <span style="color: #000000;">azimuth</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">360</span><span style="color: #0000FF;">-</span><span style="color: #000000;">azimuth</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">vmg</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">boatspeed</span><span style="color: #0000FF;">(</span><span style="color: #000000;">azimuth</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">windvelocity</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">other</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">idx</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">degrees</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">ss</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">sailingspeed</span><span style="color: #0000FF;">(</span><span style="color: #000000;">azimuth</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">degrees</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">windvelocity</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">if</span> <span style="color: #000000;">ss</span><span style="color: #0000FF;">></span><span style="color: #000000;">other</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">other</span><span style="color: #0000FF;">,</span><span style="color: #000000;">idx</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">ss</span><span style="color: #0000FF;">,</span><span style="color: #000000;">i</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #008080;">if</span> <span style="color: #000000;">other</span><span style="color: #0000FF;">></span><span style="color: #000000;">vmg</span> <span style="color: #008080;">then</span> <span style="color: #000000;">azimuth</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">degrees</span><span style="color: #0000FF;">[</span><span style="color: #000000;">idx</span><span style="color: #0000FF;">]</span> <span style="color: #000000;">vmg</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">other</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">dirchosen</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">deg2rad</span><span style="color: #0000FF;">(</span><span style="color: #000000;">winddirection</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">azimuth</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">dircurrent</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">deg2rad</span><span style="color: #0000FF;">(</span><span style="color: #000000;">currentdirection</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">wx</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">vmg</span> <span style="color: #0000FF;"></span> <span style="color: #7060A8;">sin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dirchosen</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">wy</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">vmg</span> <span style="color: #0000FF;"></span> <span style="color: #7060A8;">cos</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dirchosen</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">curx</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">currentvelocity</span> <span style="color: #0000FF;"></span> <span style="color: #7060A8;">sin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dircurrent</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">cury</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">currentvelocity</span> <span style="color: #0000FF;"></span> <span style="color: #7060A8;">cos</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dircurrent</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #7060A8;">sqrt</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">wx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">curx</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">+</span> <span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">wy</span><span style="color: #0000FF;">+</span><span style="color: #000000;">cury</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">))</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #008080;">function</span> <span style="color: #000000;">sailsegmenttime</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">surfaceparameters</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">lat1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lat2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon2</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- -- Calculate the trip time in minutes from (lat1, lon1) to the destination (lat2, lon2). -- Uses the data in surfaceparameters for wind and current velocity and direction. --</span> <span style="color: #004080;">atom</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">distance</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">direction</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">haversine</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lat1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lat2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon2</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">velocity</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">bestvectorspeed</span><span style="color: #0000FF;">(</span><span style="color: #000000;">direction</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">surfaceparameters</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- minutes/s * m / (knots * (m/s / knot)) = minutes</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">/</span><span style="color: #000000;">60</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;"></span> <span style="color: #000000;">distance</span> <span style="color: #0000FF;">/</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">velocity</span> <span style="color: #0000FF;"></span> <span style="color: #000000;">1.94384</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">return</span> <span style="color: #000000;">res</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #000080;font-style:italic;">-- -- The data is selected so the best time path is slightly longer than the -- shortest length path. The forbidden regions are x, representing land or reef. -- The allowed sailing points are . and start and finish are S and F. -- </span> <span style="color: #008080;">constant</span> <span style="color: #000000;">chart</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">split</span><span style="color: #0000FF;">(</span><span style="color: #008000;">""" ...S..... x......x. ....x..x. x...xx.x. x...xx.x. ..xxxx.xx x..xxx... .......xx x..F..x.x"""</span><span style="color: #0000FF;">,</span><span style="color: #008000;">'\n'</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">function</span> <span style="color: #000000;">minimum_time_route</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">timeframe</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">start</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">finish</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- -- Get the fastest route from start to finish for some detailed sea/ship parameters. -- timeframe is a massive 200 * 9x9 * {pt,surfaceparameters} -- note that polar data (ie winds, degrees, speeds) is static here, for simplicity. --</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">t0</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">time</span><span style="color: #0000FF;">(),</span> <span style="color: #000000;">mintime</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1000.0</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">xmax</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">chart</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]),</span> <span style="color: #000000;">ymax</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">chart</span><span style="color: #0000FF;">),</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">start</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">todo</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">start</span><span style="color: #0000FF;">},</span> <span style="color: #000000;">costs</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">xmax</span><span style="color: #0000FF;">),</span><span style="color: #000000;">ymax</span><span style="color: #0000FF;">),</span> <span style="color: #000080;font-style:italic;">-- (lowest durations)</span> <span style="color: #000000;">paths</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">xmax</span><span style="color: #0000FF;">),</span><span style="color: #000000;">ymax</span><span style="color: #0000FF;">),</span> <span style="color: #000080;font-style:italic;">-- (single backlinks)</span> <span style="color: #000000;">minpath</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span> <span style="color: #000000;">costs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span> <span style="color: #008080;">while</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">todo</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">todo</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span> <span style="color: #000000;">todo</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">todo</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">..$]</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">duration</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">costs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">]</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">sdx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">round</span><span style="color: #0000FF;">(</span><span style="color: #000000;">duration</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">timeinterval</span><span style="color: #0000FF;">),</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">timeframe</span><span style="color: #0000FF;">))+</span><span style="color: #000000;">1</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">timeframe</span><span style="color: #0000FF;">[</span><span style="color: #000000;">sdx</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">for</span> <span style="color: #000000;">nx</span><span style="color: #0000FF;">=</span><span style="color: #000000;">px</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">px</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span> <span style="color: #008080;">for</span> <span style="color: #000000;">ny</span><span style="color: #0000FF;">=</span><span style="color: #000000;">py</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">py</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span> <span style="color: #008080;">if</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">px</span> <span style="color: #008080;">or</span> <span style="color: #000000;">ny</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">py</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">and</span> <span style="color: #000000;">nx</span><span style="color: #0000FF;">>=</span><span style="color: #000000;">1</span> <span style="color: #008080;">and</span> <span style="color: #000000;">nx</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">xmax</span> <span style="color: #008080;">and</span> <span style="color: #000000;">ny</span><span style="color: #0000FF;">>=</span><span style="color: #000000;">1</span> <span style="color: #008080;">and</span> <span style="color: #000000;">ny</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">ymax</span> <span style="color: #008080;">and</span> <span style="color: #000000;">chart</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">]!=</span><span style="color: #008000;">'x'</span> <span style="color: #008080;">then</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">gp1</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">],</span> <span style="color: #000080;font-style:italic;">-- {pt,surfaceparameters}</span> <span style="color: #000000;">gp2</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">]</span> <span style="color: #000080;font-style:italic;">-- ""</span> <span style="color: #004080;">atom</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">lat1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon1</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gp1</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">],</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">lat2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon2</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gp2</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">surfaceparameters</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gp1</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">nt</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">duration</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">sailsegmenttime</span><span style="color: #0000FF;">(</span><span style="color: #000000;">surfaceparameters</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lat1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lat2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">lon2</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">if</span> <span style="color: #000000;">costs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">]=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">or</span> <span style="color: #000000;">nt</span><span style="color: #0000FF;"><</span><span style="color: #000000;">costs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span> <span style="color: #000080;font-style:italic;">-- a larger (than 9x9) simulation might benefit from not -- putting any already-too-long routes back on the todo -- list and/or processing todo lowest duration first.</span> <span style="color: #000000;">costs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">nt</span> <span style="color: #000000;">paths</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">({</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">},</span><span style="color: #000000;">todo</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #000000;">todo</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">todo</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">elsif</span> <span style="color: #000000;">nt</span><span style="color: #0000FF;">==</span><span style="color: #000000;">costs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ny</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nx</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span> <span style="color: #000080;font-style:italic;">-- (Should multiple same-time routes exist, we could store -- multiple back-links and whip up a simple [recursive] -- routine to rebuild them all. Or just ignore them.)</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span> <span style="color: #000080;font-style:italic;">-- (simplify debugging)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">while</span> <span style="color: #000000;">timeframe</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span> <span style="color: #000080;font-style:italic;">-- (simplify debugging)</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">finish</span> <span style="color: #000000;">mintime</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">costs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">]</span> <span style="color: #000000;">minpath</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">finish</span><span style="color: #0000FF;">}</span> <span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span> <span style="color: #004080;">object</span> <span style="color: #000000;">pyx</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">paths</span><span style="color: #0000FF;">[</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">if</span> <span style="color: #000000;">pyx</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000000;">minpath</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prepend</span><span style="color: #0000FF;">(</span><span style="color: #000000;">minpath</span><span style="color: #0000FF;">,</span><span style="color: #000000;">pyx</span><span style="color: #0000FF;">)</span> <span style="color: #000000;">paths</span><span style="color: #0000FF;">[</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span> <span style="color: #000080;font-style:italic;">-- (be safe, why not)</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">py</span><span style="color: #0000FF;">,</span><span style="color: #000000;">px</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">pyx</span> <span style="color: #008080;">end</span> <span style="color: #008080;">while</span> <span style="color: #008080;">if</span> <span style="color: #000000;">minpath</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]!=</span><span style="color: #000000;">start</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">minpath</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">elapsed</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mintime</span><span style="color: #0000FF;"></span><span style="color: #000000;">60</span><span style="color: #0000FF;">),</span><span style="color: #7060A8;">elapsed</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">time</span><span style="color: #0000FF;">()-</span><span style="color: #000000;">t0</span><span style="color: #0000FF;">)}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #008080;">function</span> <span style="color: #000000;">surfacebylongitude</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">lon</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- Create regional wind patterns on the map.</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">surfaceparameters</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lon</span> <span style="color: #0000FF;"><</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">155.03</span> <span style="color: #0000FF;">?</span> <span style="color: #0000FF;">{</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">5.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">8</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">150</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.5</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">:</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lon</span> <span style="color: #0000FF;"><</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">155.99</span> <span style="color: #0000FF;">?</span> <span style="color: #0000FF;">{-</span><span style="color: #000000;">90.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">20</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">150</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.4</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">:</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">180.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">25</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">150</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.3</span><span style="color: #0000FF;">}))</span> <span style="color: #008080;">return</span> <span style="color: #000000;">surfaceparameters</span> <span style="color: #008080;">end</span> <span style="color: #008080;">function</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">slices</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #004600;">null</span><span style="color: #0000FF;">,</span><span style="color: #000000;">200</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">procedure</span> <span style="color: #000000;">mutatetimeslices</span><span style="color: #0000FF;">()</span> <span style="color: #000080;font-style:italic;">-- Vary wind speeds over time.</span> <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">slices</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">deep_copy</span><span style="color: #0000FF;">(</span><span style="color: #000000;">slices</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">])</span> <span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">sj</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span> <span style="color: #008080;">for</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sj</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">windvelocity</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">sj</span><span style="color: #0000FF;">[</span><span style="color: #000000;">k</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span> <span style="color: #000000;">windvelocity</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">0.002</span><span style="color: #0000FF;"></span><span style="color: #000000;">i</span> <span style="color: #000000;">sj</span><span style="color: #0000FF;">[</span><span style="color: #000000;">k</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">windvelocity</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">sj</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #000000;">slices</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">s</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span> <span style="color: #008080;">for</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">slices</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">gpoints</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #004600;">null</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">9</span> <span style="color: #008080;">do</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">lat</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">19.78</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">/</span><span style="color: #000000;">60</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">/</span><span style="color: #000000;">60</span> <span style="color: #000000;">gpoints</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #004600;">null</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">9</span> <span style="color: #008080;">do</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">lon</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">155.0</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">6</span><span style="color: #0000FF;">/</span><span style="color: #000000;">60</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">/</span><span style="color: #000000;">60</span> <span style="color: #000000;">gpoints</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{</span><span style="color: #000000;">lat</span><span style="color: #0000FF;">,</span><span style="color: #000000;">lon</span><span style="color: #0000FF;">},</span> <span style="color: #000000;">surfacebylongitude</span><span style="color: #0000FF;">(</span><span style="color: #000000;">lon</span><span style="color: #0000FF;">)}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #000000;">slices</span><span style="color: #0000FF;">[</span><span style="color: #000000;">s</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gpoints</span> <span style="color: #008080;">end</span> <span style="color: #008080;">for</span> <span style="color: #000000;">mutatetimeslices</span><span style="color: #0000FF;">()</span> <span style="color: #008080;">constant</span> <span style="color: #000000;">fmt</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""" The route taking the least time found was: %v which has duration %s [route found in %s] """</span> <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">,</span><span style="color: #000000;">minimum_time_route</span><span style="color: #0000FF;">(</span><span style="color: #000000;">slices</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">9</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">}))</span> <span style="color: #0000FF;">{}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">wait_key</span><span style="color: #0000FF;">()</span> <!--</syntaxhighlight>--> {{out}} <pre> Line 1,555 ⟶ 1,605: As you'd expect, this takes many times longer than Julia to run (about 24.5 minutes versus 3 minutes 20 seconds) but gets there in the end :) <~~lang~~syntaxhighlight ~~ecmascript~~lang="wren">import "io" for File / Line 1,976 ⟶ 2,026: var tp = minimumTimeRoute.call(routeProb, sp, false) System.print("The route taking the least time found was:\n %(tp.path) \nwhich has duration " + "%((tp.duration/60).truncate) hours, %((tp.duration%60).round) minutes.")</~~lang~~syntaxhighlight> {{out}}