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Geohash: Difference between revisions

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Geohash (view source)

Revision as of 20:18, 18 January 2022

13,128 bytes added ,  2 years ago
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→‎{{header|Phix}}: added syntax colouring, marked p2js compatible
(Added solution for Action!)
m (→‎{{header|Phix}}: added syntax colouring, marked p2js compatible)
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=={{header|Phix}}==
<!--<lang Phix>(phixonline)-->
<lang Phix>constant gBase32 = "0123456789bcdefghjkmnpqrstuvwxyz"
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">gBase32</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"0123456789bcdefghjkmnpqrstuvwxyz"</span>
function encode_geohash(sequence location, integer precision)
sequence r = {{-90,90},{-180,180}} -- lat/long
<span style="color: #008080;">function</span> <span style="color: #000000;">encode_geohash</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">location</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">precision</span><span style="color: #0000FF;">)</span>
integer ll = 2, -- " " "
<span style="color: #004080;">sequence</span> <span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{-</span><span style="color: #000000;">90</span><span style="color: #0000FF;">,</span><span style="color: #000000;">90</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">180</span><span style="color: #0000FF;">,</span><span style="color: #000000;">180</span><span style="color: #0000FF;">}}</span> <span style="color: #000080;font-style:italic;">-- lat/long</span>
hashval = 0, bits = 0
<span style="color: #004080;">integer</span> <span style="color: #000000;">ll</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- " " "</span>
string hash = ""
<span style="color: #000000;">hashval</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">bits</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
while length(hash) < precision do
<span style="color: #004080;">string</span> <span style="color: #000000;">hash</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span>
atom mid = sum(r[ll])/2,
<span style="color: #008080;">while</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">hash</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;"><</span> <span style="color: #000000;">precision</span> <span style="color: #008080;">do</span>
gt = location[ll]>mid
<span style="color: #004080;">atom</span> <span style="color: #000000;">mid</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sum</span><span style="color: #0000FF;">(</span><span style="color: #000000;">r</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ll</span><span style="color: #0000FF;">])/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span>
hashval = hashval*2+gt
<span style="color: #000000;">gt</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">location</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ll</span><span style="color: #0000FF;">]></span><span style="color: #000000;">mid</span>
r[ll][2-gt] = mid
<span style="color: #000000;">hashval</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">hashval</span><span style="color: #0000FF;">*</span><span style="color: #000000;">2</span><span style="color: #0000FF;">+</span><span style="color: #000000;">gt</span>
bits += 1
<span style="color: #000000;">r</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ll</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">-</span><span style="color: #000000;">gt</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">mid</span>
if bits=5 then
<span style="color: #000000;">bits</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
hash &= gBase32[hashval+1]
<span style="color: #008080;">if</span> <span style="color: #000000;">bits</span><span style="color: #0000FF;">=</span><span style="color: #000000;">5</span> <span style="color: #008080;">then</span>
{hashval,bits} = {0,0}
<span style="color: #000000;">hash</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">gBase32</span><span style="color: #0000FF;">[</span><span style="color: #000000;">hashval</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
end if
<span style="color: #0000FF;">{</span><span style="color: #000000;">hashval</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bits</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">}</span>
ll = 3-ll -- (1 <==> 2)
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end while
<span style="color: #000000;">ll</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">3</span><span style="color: #0000FF;">-</span><span style="color: #000000;">ll</span> <span style="color: #000080;font-style:italic;">-- (1 &lt;==&gt; 2)</span>
return hash
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">hash</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function decode_geohash(string hash)
-- output is {{lat_lo,lat_hi},{long_lo,long_hi}}
<span style="color: #008080;">function</span> <span style="color: #000000;">decode_geohash</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">hash</span><span style="color: #0000FF;">)</span>
sequence r = {{-90,90},{-180,180}} -- lat/long
<span style="color: #000080;font-style:italic;">-- output is {{lat_lo,lat_hi},{long_lo,long_hi}}</span>
integer ll = 2 -- " " "
<span style="color: #004080;">sequence</span> <span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{-</span><span style="color: #000000;">90</span><span style="color: #0000FF;">,</span><span style="color: #000000;">90</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">180</span><span style="color: #0000FF;">,</span><span style="color: #000000;">180</span><span style="color: #0000FF;">}}</span> <span style="color: #000080;font-style:italic;">-- lat/long</span>
for h=1 to length(hash) do
<span style="color: #004080;">integer</span> <span style="color: #000000;">ll</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2</span> <span style="color: #000080;font-style:italic;">-- " " "</span>
string b = sprintf("%05b",find(hash[h],gBase32)-1)
<span style="color: #008080;">for</span> <span style="color: #000000;">h</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;">hash</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
for it=1 to 5 do
<span style="color: #004080;">string</span> <span style="color: #000000;">b</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%05b"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">hash</span><span style="color: #0000FF;">[</span><span style="color: #000000;">h</span><span style="color: #0000FF;">],</span><span style="color: #000000;">gBase32</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
r[ll][2-(b[it]='1')] = sum(r[ll])/2
<span style="color: #008080;">for</span> <span style="color: #000000;">it</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">5</span> <span style="color: #008080;">do</span>
ll = 3-ll -- (1 <==> 2)
<span style="color: #000000;">r</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ll</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">-(</span><span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">it</span><span style="color: #0000FF;">]=</span><span style="color: #008000;">'1'</span><span style="color: #0000FF;">)]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sum</span><span style="color: #0000FF;">(</span><span style="color: #000000;">r</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ll</span><span style="color: #0000FF;">])/</span><span style="color: #000000;">2</span>
end for
<span style="color: #000000;">ll</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">3</span><span style="color: #0000FF;">-</span><span style="color: #000000;">ll</span> <span style="color: #000080;font-style:italic;">-- (1 &lt;==&gt; 2)</span>
end for
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
return r
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">r</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
sequence tests = {{{51.433718, -0.214126}, 2},
{{51.433718, -0.214126}, 9},
<span style="color: #004080;">sequence</span> <span style="color: #000000;">tests</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{{</span><span style="color: #000000;">51.433718</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">0.214126</span><span style="color: #0000FF;">},</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">},</span>
{{57.64911, 10.40744 }, 11},
<span style="color: #0000FF;">{{</span><span style="color: #000000;">51.433718</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">0.214126</span><span style="color: #0000FF;">},</span> <span style="color: #000000;">9</span><span style="color: #0000FF;">},</span>
{{57.64911, 10.40744 }, 22}}
<span style="color: #0000FF;">{{</span><span style="color: #000000;">57.64911</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">10.40744</span> <span style="color: #0000FF;">},</span> <span style="color: #000000;">11</span><span style="color: #0000FF;">},</span>
<span style="color: #0000FF;">{{</span><span style="color: #000000;">57.64911</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">10.40744</span> <span style="color: #0000FF;">},</span> <span style="color: #000000;">22</span><span style="color: #0000FF;">}}</span>
for i=1 to length(tests) do
{sequence location, integer precision} = tests[i]
<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;">tests</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
string geohash = encode_geohash(location, precision)
<span style="color: #0000FF;">{</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">location</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">precision</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">tests</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
printf(1,"geohash for %v, precision %d = %s\n",{location, precision, geohash})
<span style="color: #004080;">string</span> <span style="color: #000000;">geohash</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">encode_geohash</span><span style="color: #0000FF;">(</span><span style="color: #000000;">location</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">precision</span><span style="color: #0000FF;">)</span>
tests[i] = geohash
<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: #008000;">"geohash for %v, precision %d = %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">location</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">precision</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">geohash</span><span style="color: #0000FF;">})</span>
end for
<span style="color: #000000;">tests</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;">geohash</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
printf(1,"\ndecode tests:\n")
tests = append(tests,"ezs42")
<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: #008000;">"\ndecode tests:\n"</span><span style="color: #0000FF;">)</span>
for i=1 to length(tests) do
<span style="color: #000000;">tests</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">tests</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"ezs42"</span><span style="color: #0000FF;">)</span>
printf(1,"%-22s ==> %v\n",{tests[i],decode_geohash(tests[i])})
<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;">tests</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
end for</lang>
<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: #008000;">"%-22s ==&gt; %v\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">tests</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span><span style="color: #000000;">decode_geohash</span><span style="color: #0000FF;">(</span><span style="color: #000000;">tests</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;">for</span>
<!--</lang>-->
{{out}}
<pre>
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