MAKE A MEME
View Large Image
| View Original: | Triskelion-spiral-threespoked-inspiral.png (588x600) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: Triskelion-spiral-threespoked-inspiral.png A form of a Triskelion symbol containing three double spirals which branch out into a larger spiral which encloses the whole figure Inspired by various Celtic decorative motifs but this version is constructed from mathematical Archimedean spirals Useful as an example of a wheeled type of triskelion For less ornate wheeled triskelions with partially-enclosing circle instead of enclosing spiral see Image Wheeled-Triskelion-basic png Image Roissy triskelion iron ring signet png and Image Triple-spiral-wheeled-simple png right 120px For other non-wheel versions of the triskelion or triple-spiral symbols see Image Triskele-Symbol-spiral-five-thirds-turns png Image Triple-Spiral-Symbol-filled png Image Triple-Spiral-Symbol-4turns-filled png Image Triskele-Symbol-spiral png or Image Triple-Spiral-Symbol png For a spiral triskelion with a hollow triangle in the center see Image Triskele-hollow-triangle png For versions of a triple-spiral labyrinth see Image Triple-Spiral-labyrinth png and Image Triple-Spiral-labyrinth-variant png Generated by means of the following PostScript code <pre> /archimdouble 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 centerx horizontal coordinate of center of spiral centery vertical coordinate of center of spiral rotf degrees to rotate /sepwid 110 def width separating successive turnings of spiral half this if double spiral is selected /incrm 15 def insert a curve point after this number of degrees CHANGE TO 30 EXCEPT AT TRANSITIONS /double 1 def change to 0 to display single spiral /quadruple 1 def change to 0 to display single/double spiral only Procedures /pi 3 1415926535898 def/radians 57 295779513082 def /sepwid sepwid pi div 2 div def gsave centerx centery translate rotf rotate /aspiral /prevbezy 0 def/first 1 def lower incrm sweeps 360 mul 8 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 0 eq phase 90 eq phase 270 eq or and /slope 999999999 def /slope sinth thcosth add costh thsinth sub div def ifelse sinth 0 gt sinth 0 eq costh -1 eq and or /flag -1 def /flag 1 def ifelse /A exch def phase 0 eq phase 180 eq or 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 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 0 0 moveto/prevbezx phase cos nextdist mul def/first 0 def first 1 eq x y moveto/first 0 def prevbezx prevbezy x 1 flag mul normaliz div prevdist mul sub y slope flag mul normaliz div prevdist mul sub x y curveto ifelse /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 x y moveto x 1 flag mul normaliz div nextdist mul pi mul const mul add y slope flag mul normaliz div nextdist mul pi mul const mul add lineto stroke def /sweeps 1 67 def number of 360 degree turnings to show /const 2 315 def /phase 0 def aspiral double 0 ne /sweeps 1 4584 def /const 2 621 def /phase 90 def aspiral if quadruple 0 ne /sweeps 645 1 360 div def /const 0 def /phase 180 def aspiral /sweeps 555 1 360 div def /const 0 def /phase 270 def aspiral if grestore def 68 55 translate 75 dup scale gsave 800 0 translate - 75 75 scale -20 77 rotate /lower 0 def /disp 70 rotf -56 801 sub def/trnslx disp sin neg mul disp cos mul translate def gsave /centerx 304 def/centery 550 def/rotf 125 67 def trnslx archimdouble grestore gsave /centerx 634 def/centery 550 def/rotf 245 67 def trnslx archimdouble grestore gsave /centerx 469 def/centery 835 7884 def/rotf 5 67 def trnslx archimdouble grestore grestore 75 setlinewidth 598 996 0 translate -1 1 scale 299 498 327 764 10 3125 360 0 arcn stroke 299 498 327 764 translate /sepwid 123 75 pi div 2 div def /const 0 def /incrm 30 def gsave -3 0445 rotate 1 00451 dup scale /sweeps 3 1 def /lower 870 def /phase 60 def aspiral /phase 180 def aspiral /phase 300 def aspiral grestore gsave -2 87 rotate 1 00412 dup scale /sweeps 3 27 def /lower 930 def /phase 0 def aspiral /phase 120 def aspiral /phase 240 def aspiral grestore showpage EOF</pre> 2006 AnonMoos Triskelion-spiral-threespoked-inspiral svg Triple spiral Computer generated mandalas Archimedean spirals Images with PostScript source code | ||||
