Sunflower fractal: Difference between revisions
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[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Sunflower_fractal.png Screenshot from Atari 8-bit computer]
=={{header|Applesoft BASIC}}==
<lang gwbasic>HGR:A=PEEK(49234):C=(SQR(5)+1)/2:N=900:FORI=0TO1600:R=(I^C)/N:A=2*3.141596535*C*I:X=R*SIN(A)+139:Y=R*COS(A)+96:F=7-4*((X-INT(X/2)*2)>=.75):X=(X>=0ANDX<280)*X:Y=(Y>=0ANDY<192)*Y:HCOLOR=F*(XANDY):HPLOTX,Y:NEXT</lang>
=={{header|C}}==
The colouring of the "fractal" is determined with every iteration to ensure that the resulting graphic looks similar to a real Sunflower, thus the parameter ''diskRatio'' determines the radius of the central disk as the maximum radius of the flower is known from the number of iterations. The scaling factor is currently hardcoded but can also be externalized. Requires the [http://www.cs.colorado.edu/~main/bgi/cs1300/ WinBGIm] library.
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Revision as of 18:46, 16 July 2022
Draw a Sunflower fractal
11l
<lang 11l>-V
phi = (1 + sqrt(5)) / 2 size = 600 seeds = 5 * size
print(‘<svg xmlns="http://www.w3.org/2000/svg" width="’size‘" height="’size‘" style="stroke:gold">’) print(‘<rect width="100%" height="100%" fill="black" />’)
L(i) 1..seeds
V r = 2 * (i ^ phi) / seeds V t = 2 * math:pi * phi * i print(‘<circle cx="#.2" cy="#.2" r="#.1" />’.format(r * sin(t) + size / 2, r * cos(t) + size / 2, sqrt(i) / 13))
print(‘</svg>’)</lang>
Action!
Calculations on a real Atari 8-bit computer take quite long time. It is recommended to use an emulator capable with increasing speed of Atari CPU.
<lang Action!>INCLUDE "H6:REALMATH.ACT"
INT ARRAY SinTab=[
0 4 9 13 18 22 27 31 36 40 44 49 53 58 62 66 71 75 79 83 88 92 96 100 104 108 112 116 120 124 128 132 136 139 143 147 150 154 158 161 165 168 171 175 178 181 184 187 190 193 196 199 202 204 207 210 212 215 217 219 222 224 226 228 230 232 234 236 237 239 241 242 243 245 246 247 248 249 250 251 252 253 254 254 255 255 255 256 256 256 256]
INT FUNC Sin(INT a)
WHILE a<0 DO a==+360 OD WHILE a>360 DO a==-360 OD IF a<=90 THEN RETURN (SinTab(a)) ELSEIF a<=180 THEN RETURN (SinTab(180-a)) ELSEIF a<=270 THEN RETURN (-SinTab(a-180)) ELSE RETURN (-SinTab(360-a)) FI
RETURN (0)
INT FUNC Cos(INT a) RETURN (Sin(a-90))
PROC Circle(INT x0,y0,d)
BYTE MaxD=[13] BYTE ARRAY Start=[0 1 2 4 6 9 12 16 20 25 30 36 42 49] BYTE ARRAY MaxY=[0 0 1 1 2 2 3 3 4 4 5 5 6 6] INT ARRAY CircleX=[ 0 0 1 0 1 1 2 1 0 2 2 1 3 2 2 0 3 3 2 1 4 4 3 2 1 4 4 4 3 2 5 5 4 4 3 1 5 5 5 4 4 2 6 6 5 5 4 3 1 6 6 6 5 5 4 2]
INT i,ind,max CARD x BYTE dx,y
IF d>MAXD THEN d=MaxD FI IF d<0 THEN d=0 FI
ind=Start(d) max=MaxY(d) FOR i=0 TO max DO dx=CircleX(ind) y=y0-i IF (y>=0) AND (y<=191) THEN Plot(x0-dx,y) DrawTo(x0+dx,y) FI y=y0+i IF (y>=0) AND (y<=191) THEN Plot(x0-dx,y) DrawTo(x0+dx,y) FI ind==+1 OD
RETURN
PROC DrawFractal(CARD seeds INT x0,y0)
CARD i REAL a,c,r,ir,tmp,tmp2,r256,rx,ry,rr,r360,c360,seeds2 INT ia,sc,x,y
IntToReal(256,r256) ValR("1.618034",c) ;c=(sqrt(5)+1)/2 IntToReal(seeds/2,seeds2) ;seeds2=seeds/2 IntToReal(360,r360) RealMult(r360,c,c360) ;c360=360*c
FOR i=0 TO seeds DO IntToReal(i,ir) Power(ir,c,tmp) RealDiv(tmp,seeds2,r) ;r=i^c/(seeds/2) RealMult(c360,ir,a) ;a=360*c*i
WHILE RealGreaterOrEqual(a,r360) DO RealSub(a,r360,tmp) RealAssign(tmp,a) OD
ia=RealToInt(a) sc=Sin(ia) IntToRealForNeg(sc,tmp) RealDiv(tmp,r256,tmp2) RealMult(r,tmp2,rx) x=Round(rx) ;x=r*sin(a) sc=Cos(ia) IntToRealForNeg(sc,tmp) RealDiv(tmp,r256,tmp2) RealMult(r,tmp2,ry) y=Round(ry) ;y=r*cos(a)
Circle(x+x0,y+y0,10*i/seeds)
Poke(77,0) ;turn off the attract mode OD
RETURN
PROC Main()
BYTE CH=$02FC,COLOR1=$02C5,COLOR2=$02C6
Graphics(8+16) Color=1 COLOR1=$12 COLOR2=$18
DrawFractal(1000,160,96)
DO UNTIL CH#$FF OD CH=$FF
RETURN</lang>
- Output:
Screenshot from Atari 8-bit computer
Applesoft BASIC
<lang gwbasic>HGR:A=PEEK(49234):C=(SQR(5)+1)/2:N=900:FORI=0TO1600:R=(I^C)/N:A=2*3.141596535*C*I:X=R*SIN(A)+139:Y=R*COS(A)+96:F=7-4*((X-INT(X/2)*2)>=.75):X=(X>=0ANDX<280)*X:Y=(Y>=0ANDY<192)*Y:HCOLOR=F*(XANDY):HPLOTX,Y:NEXT</lang>
C
The colouring of the "fractal" is determined with every iteration to ensure that the resulting graphic looks similar to a real Sunflower, thus the parameter diskRatio determines the radius of the central disk as the maximum radius of the flower is known from the number of iterations. The scaling factor is currently hardcoded but can also be externalized. Requires the WinBGIm library.
<lang C> /*Abhishek Ghosh, 14th September 2018*/
- include<graphics.h>
- include<math.h>
- define pi M_PI
void sunflower(int winWidth, int winHeight, double diskRatio, int iter){ double factor = .5 + sqrt(1.25),r,theta; double x = winWidth/2.0, y = winHeight/2.0; double maxRad = pow(iter,factor)/iter;
int i;
setbkcolor(LIGHTBLUE);
for(i=0;i<=iter;i++){ r = pow(i,factor)/iter;
r/maxRad < diskRatio?setcolor(BLACK):setcolor(YELLOW);
theta = 2*pi*factor*i; circle(x + r*sin(theta), y + r*cos(theta), 10 * i/(1.0*iter)); } }
int main() { initwindow(1000,1000,"Sunflower...");
sunflower(1000,1000,0.5,3000);
getch();
closegraph();
return 0; } </lang>
C++
<lang cpp>#include <cmath>
- include <fstream>
- include <iostream>
bool sunflower(const char* filename) {
std::ofstream out(filename); if (!out) return false;
constexpr int size = 600; constexpr int seeds = 5 * size; constexpr double pi = 3.14159265359; constexpr double phi = 1.61803398875; out << "<svg xmlns='http://www.w3.org/2000/svg\' width='" << size; out << "' height='" << size << "' style='stroke:gold'>\n"; out << "<rect width='100%' height='100%' fill='black'/>\n"; out << std::setprecision(2) << std::fixed; for (int i = 1; i <= seeds; ++i) { double r = 2 * std::pow(i, phi)/seeds; double theta = 2 * pi * phi * i; double x = r * std::sin(theta) + size/2; double y = r * std::cos(theta) + size/2; double radius = std::sqrt(i)/13; out << "<circle cx='" << x << "' cy='" << y << "' r='" << radius << "'/>\n"; } out << "</svg>\n"; return true;
}
int main(int argc, char *argv[]) {
if (argc != 2) { std::cerr << "usage: " << argv[0] << " filename\n"; return EXIT_FAILURE; } if (!sunflower(argv[1])) { std::cerr << "image generation failed\n"; return EXIT_FAILURE; } return EXIT_SUCCESS;
}</lang>
- Output:
See: sunflower.svg (offsite SVG image)
FreeBASIC
<lang freebasic> Const PI As Double = 4 * Atn(1) Const ancho = 400 Const alto = 400
Screenres ancho, alto, 8 Windowtitle" Pulsa una tecla para finalizar" Cls
Sub Sunflower(semillas As Integer)
Dim As Double c = (Sqr(5)+1)/2 For i As Integer = 0 To semillas Dim As Double r = (i^c) / semillas Dim As Double angulo = 2 * Pi * c * i Dim As Double x = r * Sin(angulo) + 200 Dim As Double y = r * Cos(angulo) + 200 Circle (x, y), i/semillas*10, i/semillas*10 Next i
End Sub
Sunflower(2000) Bsave "sunflower_fractal.bmp",0 Sleep End </lang>
Go
The image produced, when viewed with (for example) EOG, is similar to the Ring entry.
<lang go>package main
import (
"github.com/fogleman/gg" "math"
)
func main() {
dc := gg.NewContext(400, 400) dc.SetRGB(1, 1, 1) dc.Clear() dc.SetRGB(0, 0, 1) c := (math.Sqrt(5) + 1) / 2 numberOfSeeds := 3000 for i := 0; i <= numberOfSeeds; i++ { fi := float64(i) fn := float64(numberOfSeeds) r := math.Pow(fi, c) / fn angle := 2 * math.Pi * c * fi x := r*math.Sin(angle) + 200 y := r*math.Cos(angle) + 200 fi /= fn / 5 dc.DrawCircle(x, y, fi) } dc.SetLineWidth(1) dc.Stroke() dc.SavePNG("sunflower_fractal.png")
}</lang>
JavaScript
HTML to test
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>Sunflower</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <style> body{background-color:black;text-align:center;margin-top:150px} </style> <script src="sunflower.js"></script> </head> <body onload="start()"> <div id='wnd'></div> </body> </html>
<lang javascript>const SIZE = 400, HS = SIZE >> 1, WAIT = .005, SEEDS = 3000,
TPI = Math.PI * 2, C = (Math.sqrt(10) + 1) / 2;
class Sunflower {
constructor() { this.wait = WAIT; this.colorIndex = 0; this.dimension = 0; this.lastTime = 0; this.accumulator = 0; this.deltaTime = 1 / 60; this.colors = ["#ff0000", "#ff8000", "#ffff00", "#80ff00", "#00ff00", "#00ff80", "#00ffff", "#0080ff", "#0000ff", "#8000ff", "#ff00ff", "#ff0080"]; this.canvas = document.createElement('canvas'); this.canvas.width = SIZE; this.canvas.height = SIZE; const d = document.getElementById("wnd"); d.appendChild(this.canvas); this.ctx = this.canvas.getContext('2d'); } draw(clr, d) { let r = Math.pow(d, C) / SEEDS; let angle = TPI * C * d; let x = HS + r * Math.sin(angle), y = HS + r * Math.cos(angle); this.ctx.strokeStyle = clr; this.ctx.beginPath(); this.ctx.arc(x, y, d / (SEEDS / 50), 0, TPI); this.ctx.closePath(); this.ctx.stroke(); } update(dt) { if((this.wait -= dt) < 0) { this.draw(this.colors[this.colorIndex], this.dimension); this.wait = WAIT; if((this.dimension++) > 600) { this.dimension = 0; this.colorIndex = (this.colorIndex + 1) % this.colors.length; } } } start() { this.loop = (time) => { this.accumulator += (time - this.lastTime) / 1000; while(this.accumulator > this.deltaTime) { this.accumulator -= this.deltaTime; this.update(Math.min(this.deltaTime)); } this.lastTime = time; requestAnimationFrame(this.loop); } this.loop(0); }
} function start() {
const sunflower = new Sunflower(); sunflower.start();
}</lang>
J
This (currently draft) task really needs an adequate description. Still, it's straightforward to derive code from another implementation on this page.
This implementation assumes a recent J implementation (for example, J903):
<lang J>require'format/printf'
sunfract=: {{ NB. y: number of "sunflower seeds"
phi=. 0.5*1+%:5 XY=. (y%10)+(2*(I^phi)%y) * +.^j.2*1p1*phi*I=.1+i.y XY,.(%:I)%13
}}
sunfractsvg=: {{
fract=. sunfract x C=.,'\n<circle cx="%.2f" cy="%.2f" r="%.1f" />' sprintf fract ({{)n <svg xmlns="http://www.w3.org/2000/svg" width="%d" height="%d" style="stroke:gold"> <rect width="100%%" height="100%%" fill="black" /> %s </svg>
}} sprintf (;/<.20+}:>./fract),<C) fwrite y}} </lang>
Example use:
<lang J>
3000 sunfractsvg '~/sunfract.html'
129147 </lang>
(The number displayed is the size of the generated file.)
jq
Adapted from Perl
Works with gojq, the Go implementation of jq
<lang jq># SVG headers def svg(size):
"<svg xmlns='http://www.w3.org/2000/svg' width='\(size)'", "height='\(size)' style='stroke:gold'>", "<rect width='100%' height='100%' fill='black'/>";
- emit the "<circle />" elements
def sunflower(size):
def rnd: 100*.|round/100;
(5 * size) as $seeds | ((1|atan) * 4) as $pi | ((1 + (5|sqrt)) / 2) as $phi | range(1; 1 + $seeds) as $i | {} | .r = 2 * pow($i; $phi)/$seeds | .theta = 2 * $pi * $phi * $i | .x = .r * (.theta|sin) + size/2 | .y = .r * (.theta|cos) + size/2 | .radius = ($i|sqrt)/13 | "<circle cx='\(.x|rnd)' cy='\(.y|rnd)' r='\(.radius|rnd)' />" ;
def end_svg:
"</svg>";
svg(600), sunflower(600), end_svg</lang>
Julia
Run from REPL. <lang julia>using Makie
function sunflowerplot()
len = 2000 ϕ = 0.5 + sqrt(5) / 2 r = LinRange(0.0, 100.0, len) θ = zeros(len) markersizes = zeros(Int, len) for i in 2:length(r) θ[i] = θ[i - 1] + 2π * ϕ markersizes[i] = div(i, 500) + 3 end x = r .* cos.(θ) y = r .* sin.(θ) scene = Scene(backgroundcolor=:green) scatter!(scene, x, y, color=:gold, markersize=markersizes, strokewidth=1, fill=false, show_axis=false)
end
sunflowerplot() </lang>
Liberty BASIC
<lang lb> nomainwin UpperLeftX=1:UpperLeftY=1 WindowWidth=800:WindowHeight=600 open "Sunflower Fractal" for graphics_nf_nsb as #1
- 1 "trapclose [q];down;fill darkred;flush;size 3"
c=1.618033988749895 seeds=8000 rd=gn=bl=int(rnd(1)*255)
for i=0 to seeds rd=rd+5:if rd>254 then rd=1 gn=gn+3:if gn>254 then gn=1 bl=bl+1:if bl>254 then bl=1 #1 "color ";rd;" ";gn;" ";bl #1 "backcolor ";rd;" ";gn;" ";bl r=(i^c)/seeds angle=2*3.14159*c*i x=r*sin(angle)+400 y=r*cos(angle)+280 #1 "place ";x;" ";y #1 "circlefilled ";i/seeds*5 scan next i wait
[q]
close #1 end
</lang>
Mathematica / Wolfram Language
<lang Mathematica>numseeds = 3000; pts = Table[
i = N[ni]; r = i^GoldenRatio/numseeds; t = 2 Pi GoldenRatio i; Circle[AngleVector[{r, t}], i/(numseeds/3)] , {ni, numseeds} ];
Graphics[pts]</lang>
Microsoft Small Basic
<lang smallbasic>' Sunflower fractal - 24/07/2018
GraphicsWindow.Width=410 GraphicsWindow.Height=400 c=(Math.SquareRoot(5)+1)/2 numberofseeds=3000 For i=0 To numberofseeds r=Math.Power(i,c)/numberofseeds angle=2*Math.Pi*c*i x=r*Math.Sin(angle)+200 y=r*Math.Cos(angle)+200 GraphicsWindow.DrawEllipse(x, y, i/numberofseeds*10, i/numberofseeds*10) EndFor </lang>
- Output:
Nim
<lang Nim>import math import imageman
const
Size = 600 Background = ColorRGBU [byte 0, 0, 0] Foreground = ColorRGBU [byte 0, 255, 0] C = (sqrt(5.0) + 1) / 2 NumberOfSeeds = 6000 Fn = float(NumberOfSeeds)
var image = initImage[ColorRGBU](Size, Size) image.fill(Background)
for i in 0..<NumberOfSeeds:
let fi = float(i) r = pow(fi, C) / Fn angle = 2 * PI * C * fi x = toInt(r * sin(angle) + Size div 2) y = toInt(r * cos(angle) + Size div 2) image.drawCircle(x, y, toInt(8 * fi / Fn), Foreground)
image.savePNG("sunflower.png", compression = 9)</lang>
Objeck
<lang perl>use Game.SDL2; use Game.Framework;
class Test {
@framework : GameFramework; @colors : Color[]; function : Main(args : String[]) ~ Nil { Test->New()->Run(); } New() { @framework := GameFramework->New(GameConsts->SCREEN_WIDTH, GameConsts->SCREEN_HEIGHT, "Test"); @framework->SetClearColor(Color->New(0, 0, 0)); @colors := Color->New[2]; @colors[0] := Color->New(255,128,0); @colors[1] := Color->New(255,255,25); } method : Run() ~ Nil { if(@framework->IsOk()) { e := @framework->GetEvent(); quit := false; while(<>quit) { # process input while(e->Poll() <> 0) { if(e->GetType() = EventType->SDL_QUIT) { quit := true; }; };
@framework->FrameStart(); Render(525,525,0.50,3000); @framework->FrameEnd(); }; } else { "--- Error Initializing Environment ---"->ErrorLine(); return; };
leaving { @framework->Quit(); }; }
method : Render(winWidth : Int, winHeight : Int, diskRatio : Float, iter : Int) ~ Nil { renderer := @framework->GetRenderer();
@framework->Clear();
factor := 0.5 + 1.25->SquareRoot(); x := winWidth / 2.0; y := winHeight / 2.0; maxRad := Float->Power(iter, factor) / iter;
for(i:=0;i<=iter;i+=1;) { r := Float->Power(i,factor)/iter; color := r/maxRad < diskRatio ? @colors[0] : @colors[1]; theta := 2*Float->Pi()*factor*i; renderer->CircleColor(x + r*theta->Sin(), y + r*theta->Cos(), 10 * i/(1.0*iter), color); }; @framework->Show(); }
}
consts GameConsts {
SCREEN_WIDTH := 640, SCREEN_HEIGHT := 480
} </lang>
Perl
<lang perl>use utf8; use constant π => 3.14159265; use constant φ => (1 + sqrt(5)) / 2;
my $scale = 600; my $seeds = 5*$scale;
print qq{<svg xmlns="http://www.w3.org/2000/svg" width="$scale" height="$scale" style="stroke:gold">
<rect width="100%" height="100%" fill="black" />\n};
for $i (1..$seeds) {
$r = 2 * ($i**φ) / $seeds; $t = 2 * π * φ * $i; $x = $r * sin($t) + $scale/2; $y = $r * cos($t) + $scale/2; printf qq{<circle cx="%.2f" cy="%.2f" r="%.1f" />\n}, $x, $y, sqrt($i)/13;
}
print "</svg>\n";</lang> See Phi-packing image (SVG image)
Phix
You can run this online here.
with javascript_semantics constant numberofseeds = 3000 include pGUI.e Ihandle dlg, canvas cdCanvas cddbuffer, cdcanvas function redraw_cb(Ihandle /*ih*/, integer /*posx*/, integer /*posy*/) integer {hw, hh} = sq_floor_div(IupGetIntInt(canvas, "DRAWSIZE"),2) atom s = min(hw,hh)/150, f = min(hw,hh)*8/125 cdCanvasActivate(cddbuffer) cdCanvasClear(cddbuffer) atom c = (sqrt(5)+1)/2 for i=0 to numberofseeds do atom r = power(i,c)/numberofseeds, angle = 2*PI*c*i, x = s*r*sin(angle)+hw, y = s*r*cos(angle)+hh cdCanvasCircle(cddbuffer,x,y,i/numberofseeds*f) end for cdCanvasFlush(cddbuffer) return IUP_DEFAULT end function function map_cb(Ihandle ih) cdcanvas = cdCreateCanvas(CD_IUP, ih) cddbuffer = cdCreateCanvas(CD_DBUFFER, cdcanvas) cdCanvasSetBackground(cddbuffer, CD_WHITE) cdCanvasSetForeground(cddbuffer, CD_BLACK) return IUP_DEFAULT end function procedure main() IupOpen() canvas = IupCanvas(NULL) IupSetAttribute(canvas, "RASTERSIZE", "602x502") -- initial size IupSetCallback(canvas, "MAP_CB", Icallback("map_cb")) dlg = IupDialog(canvas) IupSetAttribute(dlg, "TITLE", "Sunflower") IupSetCallback(canvas, "ACTION", Icallback("redraw_cb")) IupShow(dlg) IupSetAttribute(canvas, "RASTERSIZE", NULL) -- release the minimum limitation if platform()!=JS then IupMainLoop() IupClose() end if end procedure main()
Processing
<lang java> //Abhishek Ghosh, 26th June 2022
size(1000,1000); surface.setTitle("Sunflower...");
int iter = 3000; float factor = .5 + sqrt(1.25),r,theta,diskRatio=0.5; float x = width/2.0, y = height/2.0; double maxRad = pow(iter,factor)/iter; int i;
background(#add8e6); //Lightblue background
for(i=0;i<=iter;i++){
r = pow(i,factor)/iter;
if(r/maxRad < diskRatio){ stroke(#000000); // Black central disk } else stroke(#ffff00); // Yellow Petals
theta = 2*PI*factor*i; ellipse(x + r*sin(theta), y + r*cos(theta), 10 * i/(1.0*iter),10 * i/(1.0*iter));
} </lang>
Python
<lang python> from turtle import * from math import *
- Based on C implementation
iter = 3000 diskRatio = .5
factor = .5 + sqrt(1.25)
screen = getscreen()
(winWidth, winHeight) = screen.screensize()
- x = winWidth/2.0
- y = winHeight/2.0
x = 0.0 y = 0.0
maxRad = pow(iter,factor)/iter;
bgcolor("light blue")
hideturtle()
tracer(0, 0)
for i in range(iter+1):
r = pow(i,factor)/iter; if r/maxRad < diskRatio: pencolor("black") else: pencolor("yellow") theta = 2*pi*factor*i; up() setposition(x + r*sin(theta), y + r*cos(theta)) down() circle(10.0 * i/(1.0*iter))
update()
done() </lang>
R
<lang R> phi=1/2+sqrt(5)/2 r=seq(0,1,length.out=2000) theta=numeric(length(r)) theta[1]=0 for(i in 2:length(r)){
theta[i]=theta[i-1]+phi*2*pi
} x=r*cos(theta) y=r*sin(theta) par(bg="black") plot(x,y) size=seq(.5,2,length.out = length(x)) thick=seq(.1,2,length.out = length(x)) for(i in 1:length(x)){
points(x[i],y[i],cex=size[i],lwd=thick[i],col="goldenrod1")
} </lang>
- Output:
Racket
<lang racket>#lang racket
(require 2htdp/image)
(define N 3000) (define DISK-RATIO 0.5) (define factor (+ 0.5 (sqrt 1.25))) (define WIDTH 500) (define HEIGHT 500) (define max-rad (/ (expt N factor) N))
(for/fold ([image (empty-scene WIDTH HEIGHT)]) ([i (in-range N)])
(define r (/ (expt i factor) N)) (define color (if (< (/ r max-rad) DISK-RATIO) 'brown 'darkyellow)) (define theta (* 2 pi factor i)) (place-image (circle (* 10 i (/ 1 N)) 'outline color) (+ (/ WIDTH 2) (* r (sin theta))) (+ (/ HEIGHT 2) (* r (cos theta))) image))</lang>
Raku
(formerly Perl 6)
This is not really a fractal. It is more accurately an example of a Fibonacci spiral or Phi-packing.
Or, to be completely accurate: It is a variation of a generative Fermat's spiral using the Vogel model to implement phi-packing. See: https://thatsmaths.com/2014/06/05/sunflowers-and-fibonacci-models-of-efficiency
<lang perl6>use SVG;
my $seeds = 3000; my @center = 300, 300; my $scale = 5;
constant \φ = (3 - 5.sqrt) / 2;
my @c = map {
my ($x, $y) = ($scale * .sqrt) «*« |cis($_ * φ * τ).reals »+« @center; [ $x.round(.01), $y.round(.01), (.sqrt * $scale / 100).round(.1) ]
}, 1 .. $seeds;
say SVG.serialize(
svg => [ :600width, :600height, :style<stroke:yellow>, :rect[:width<100%>, :height<100%>, :fill<black>], |@c.map( { :circle[:cx(.[0]), :cy(.[1]), :r(.[2])] } ), ],
);</lang> See: Phi packing (SVG image)
Ring
<lang ring>
- Project : Sunflower fractal
load "guilib.ring"
paint = null
new qapp
{ win1 = new qwidget() { setwindowtitle("Sunflower fractal") setgeometry(100,100,320,500) label1 = new qlabel(win1) { setgeometry(10,10,400,400) settext("") } new qpushbutton(win1) { setgeometry(100,400,100,30) settext("draw") setclickevent("draw()") } show() } exec() }
func draw
p1 = new qpicture() color = new qcolor() { setrgb(0,0,255,255) } pen = new qpen() { setcolor(color) setwidth(1) } paint = new qpainter() { begin(p1) setpen(pen)
c = (sqrt(5) + 1) / 2 numberofseeds = 3000 for i = 0 to numberofseeds r = pow(i, c ) / (numberofseeds) angle = 2 * 3.14 * c * i x = r * sin(angle) + 100 y = r * cos(angle) + 100 drawellipse(x, y, i / (numberofseeds / 10), i / (numberofseeds / 10)) next
endpaint() } label1 { setpicture(p1) show() }
</lang> Output:
Sidef
<lang ruby>require('Imager')
func draw_sunflower(seeds=3000) {
var img = %O<Imager>.new( xsize => 400, ysize => 400, )
var c = (sqrt(1.25) + 0.5) { |i| var r = (i**c / seeds) var θ = (2 * Num.pi * c * i) var x = (r * sin(θ) + 200) var y = (r * cos(θ) + 200) img.circle(x => x, y => y, r => i/(5*seeds)) } * seeds
return img
}
var img = draw_sunflower() img.write(file => "sunflower.png")</lang> Output image: Sunflower fractal
Vlang
<lang vlang>import gg import gx import math
fn main() {
mut context := gg.new_context( bg_color: gx.rgb(255, 255, 255) width: 400 height: 400 frame_fn: frame ) context.run()
}
fn frame(mut ctx gg.Context) {
ctx.begin() c := (math.sqrt(5) + 1) / 2 num_of_seeds := 3000 for i := 0; i <= num_of_seeds; i++ { mut fi := f64(i) n := f64(num_of_seeds) r := math.pow(fi, c) / n angle := 2 * math.pi * c * fi x := r*math.sin(angle) + 200 y := r*math.cos(angle) + 200 fi /= n / 5 ctx.draw_circle_filled(f32(x), f32(y), f32(fi), gx.black) } ctx.end()
}</lang>
Wren
<lang ecmascript>import "graphics" for Canvas, Color import "dome" for Window
class Game {
static init() { Window.title = "Sunflower fractal" var width = 400 var height = 400 Window.resize(width, height) Canvas.resize(width, height) Canvas.cls(Color.black) var col = Color.green var seeds = 3000 sunflower(seeds, col) }
static update() {}
static draw(alpha) {}
static sunflower(seeds, col) { var c = (5.sqrt + 1) / 2 for (i in 0..seeds) { var r = i.pow(c) / seeds var angle = 2 * Num.pi * c * i var x = r*angle.sin + 200 var y = r*angle.cos + 200 Canvas.circle(x, y, i/seeds*5, col) } }
}</lang>
Yabasic
<lang Yabasic>// Rosetta Code problem: http://rosettacode.org/wiki/Sunflower_fractal // Adapted from Wren to Yabasic by Galileo, 01/2022
width = 400 height = 400
open window width, height backcolor 0,0,0 clear window
color 0,255,0 seeds = 3000
c = (sqrt(5) + 1) / 2 for i = 0 to seeds
r = (i ** c) / seeds angle = 2 * pi * c * i x = r * sin(angle) + 200 y = r * cos(angle) + 200 circle x, y, i / seeds * 5
next</lang>
zkl
Uses Image Magick and the PPM class from http://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm#zkl <lang zkl>fcn sunflower(seeds=3000){
img,color := PPM(400,400), 0x00ff00; // green c:=((5.0).sqrt() + 1)/2; foreach n in ([0.0 .. seeds]){ // floats r:=n.pow(c)/seeds; x,y := r.toRectangular(r.pi*c*n*2); r=(n/seeds*5).toInt(); img.circle(200 + x, 200 + y, r,color); } img.writeJPGFile("sunflower.zkl.jpg");
}();</lang>
- Output:
Image at sunflower fractal
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