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| Keywords: Archimedean spiral.png Three 360° turnings of one arm of an Archimedean spiral Produced with the following PostScript code <pre> 75 setgray 2 setlinewidth 280 640 moveto 0 -540 rlineto stroke 16 396 moveto 580 0 rlineto stroke 1 0 0 setrgbcolor PostScript program to display an Archimedean spiral by approximating it with Bezier curves Can display a double spiral two spirals rotated by 180 degrees with respect to each other Parameters /sepwid 100 def width separating successive turnings of spiral half this if double spiral is selected /incrm 11 25 def insert a curve point after this number of degrees /sweeps 3 def number of 360 degree turnings to show /centerx 280 def horizontal coordinate of center of spiral /centery 396 def vertical coordinate of center of spiral /double 0 def change to 1 to display double spiral /linew 3 def increase number for thicker line Procedures /pi 3 1415926535898 def/radians 57 295779513082 def /sepwid sepwid pi div 2 div def gsave centerx centery translate linew setlinewidth /aspiral /prevbezy 0 def 0 0 moveto 0 incrm sweeps 360 mul 7 dup repeat phase add cos/costh exch def phase add sin/sinth exch def costh mul radians div/thcosth exch def sinth mul radians div/thsinth exch def thcosth sepwid mul/x exch def thsinth sepwid mul/y exch def /slope sinth thcosth add costh thsinth sub div def sinth 0 gt sinth 0 eq costh -1 eq and or /flag -1 def /flag 1 def ifelse /A exch def A 49 29348 lt A 180 gt A 196 273450852 lt and A 360 gt A 368 8301 lt and A 540 gt A 545 9907 lt and A 720 gt A 724 5217 lt and A 900 gt A 903 6281968 lt and or or or or or /flag flag neg def if incrm sub 3 dup repeat phase add cos sepwid mul mul radians div /prevx exch def phase add sin sepwid mul mul radians div /prevy exch def incrm add 3 dup repeat phase add cos sepwid mul mul radians div /nextx exch def phase add sin sepwid mul mul radians div /nexty exch def /prevdist x prevx sub dup mul y prevy sub dup mul add sqrt pi div def /nextdist x nextx sub dup mul y nexty sub dup mul add sqrt pi div def /normaliz slope slope mul 1 add sqrt def 0 eq /prevbezx phase cos nextdist mul def prevbezx prevbezy x 1 flag mul normaliz div prevdist mul sub y slope flag mul normaliz div prevdist mul sub x y curveto /prevbezx x 1 flag mul normaliz div nextdist mul add def /prevbezy y slope flag mul normaliz div nextdist mul add def ifelse for stroke def /phase 0 def aspiral If different sweeps parameter for second spiral define here double 0 ne /phase 180 def aspiral if grestore showpage EOF</pre> 2005-10-23 User AnonMoos Archimedean spiral svg to reflect new version of image </nowiki> - 23 05 16 November 2005 en User AnonMoos <nowiki> add category </nowiki> - 12 59 23 October 2005 en User AnonMoos <nowiki> tweaking </nowiki> - 02 16 23 October 2005 en User AnonMoos †’Summary - 01 40 23 October 2005 en User AnonMoos - 01 38 23 October 2005 en User AnonMoos <nowiki> tags </nowiki> - 01 20 23 October 2005 en User AnonMoos <nowiki> One arm of an Archimedean spiral higher-resolution picture Produced with the following PostScript code 75 setgray 2 setlinewidth 280 640 moveto 0 -540 rlineto stroke 16 396 moveto 580 0 rlineto stroke 1 0 0 setrgbcolor 1 setlinecap </nowiki> Upload history on en wikipedia del cur 22 38 20 November 2005 en User AnonMoos AnonMoos en User_talk AnonMoos Talk 656x600 9955 bytes larger slightly-corrected version del rev 01 20 23 October 2005 en User AnonMoos AnonMoos en User_talk AnonMoos Talk 600x550 9150 bytes One arm of an Archimedean spiral higher-resolution picture Produced with the following PostScript code <nowiki> 75 setgray 2 setlinewidth 280 640 moveto 0 -540 rlineto stroke 16 396 moveto 580 0 rlineto stroke 1 0 0 setrgbcolor 1 setlinecap Archimedean spirals Images with PostScript source code | ||||
