File:Triskele-Symbol-spiral.svg

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Triskele-Symbol-spiral.svg‎ (SVG file, nominally 639 × 600 pixels, file size: 13 KB)

[edit] Summary

A spiral Triskelion symbol, constructed from mathematical Archimedean spirals. For a less elaborate version, see Image:Triskele-Symbol-spiral-five-thirds-turns.svg . For a more elaborate spiral triskelion symbol (with three turns instead of two), see Image:Triple-Spiral-Symbol-filled.svg, and for the most elaborate version, see Image:Triple-Spiral-Symbol-4turns-filled.svg. For a basic triple-spiral, see Image:Triple-Spiral-Symbol.svg, and for "wheeled" forms of the spiral triskelion/triple spiral symbol, see Image:Wheeled-Triskelion-basic.svg , Image:Roissy triskelion iron ring signet.png , Image:Triple-spiral-wheeled-simple.svg , or Image:Triskelion-spiral-threespoked-inspiral.svg . For a spiral triskelion with a hollow triangle in the center, see Image:Triskele-hollow-triangle.svg . For versions of a triple-spiral labyrinth, see Image:Triple-Spiral-labyrinth.svg and Image:Triple-Spiral-labyrinth-variant.svg .


SVG version of Image:Triskele-Symbol-spiral.png .

Converted from the following PostScript code:

%!
/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
/sweeps 2 def    % number of 360 degree turnings to show
/double 1 def    % change to 0 to display single spiral
%%%  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 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:
/sweeps 1.67 def
%%%
double 0 ne{/phase 180 def aspiral}if grestore
%%%%%%%%%%%%%%%%
}def
gsave
712 -134 translate -.75 .75 scale -3 rotate
/centerx 304 def/centery 550 def/rotf 0 def archimdouble
/centerx 707.333 def/centery 550 def/rotf 120 def archimdouble
/centerx 505.667 def/centery 899.2967 def/rotf 240 def archimdouble
grestore
showpage
%EOF

[edit] Licensing

Public domain I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current23:24, 12 April 2011Thumbnail for version as of 23:24, 12 April 2011639 × 600 (13 KB)Tael (We don't need a white background.)
23:23, 12 April 2011Thumbnail for version as of 23:23, 12 April 2011639 × 600 (13 KB)Tael (SVG without xmlns attribute is not displayed correctly in some browsers.)
12:28, 18 December 2006Thumbnail for version as of 12:28, 18 December 2006639 × 600 (13 KB)AnonMoos (adding white background)
06:53, 7 July 2006Thumbnail for version as of 06:53, 7 July 2006639 × 600 (13 KB)AnonMoos (== Summary == A spiral Triskelion symbol, constructed from mathematical Archimedean spirals. For a less elaborate version, see Image:Triskele-Symbol-spiral-five-thirds-turns.svg . For a more elaborate spiral triskelion)

Global file usage

Metadata

This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. If the file has been modified from its original state, some details may not fully reflect the modified file.
Width 639
Height 600
Short title Spiral triskelion (formed from mathematical Archimedean spirals), occasionally used as a Christian Trinitarian symbol
Retrieved from "http://en.wikipedia.org/wiki/File:Triskele-Symbol-spiral.svg"
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