Image:Archimedean spiral.png
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Archimedean_spiral.png (10KB, MIME type: image/png
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This is a file from the Wikimedia Commons. The description on its description page there is shown below. |
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eo: La bildo estas kopiita de wikipedia:en. La originala priskribo estas:
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[edit] Summary
Three 360° turnings of 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 %%%%%%%%%%%%%%%% % 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
[edit] Licensing
This image has been released into the public domain by its author, AnonMoos. This applies worldwide. In some countries this may not be legally possible; if so: |
[edit] Edit history on en.wikipedia
date/time | username | edit summary |
---|---|---|
22:42, 20 November 2005 | en:User:AnonMoos | (update description to reflect new version of image) |
23:05, 16 November 2005 | en:User:AnonMoos | (add category) |
12:59, 23 October 2005 | en:User:AnonMoos | (tweaking) |
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 | (tags) |
01:20, 23 October 2005 | en:User:AnonMoos | (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 %%%%%) |
[edit] Upload history on en.wikipedia
Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version.
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- (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 %%%%%)