%!PS
% this Postscript program displays the gear ratios for given gears

%enter your gears here
/rear [ 12 13 14 15 16 17 19 21 25 30 ] def
/front [ 24 39 46 ] def

% the rest is magic
/over {1 index} def
/pick {index} def
/drop {pop} def
/swap {exch} def

1 setlinejoin
0 0 translate
%.91 .91 scale
0.3 setlinewidth

%transformation
/tf {swap ln 1 add 200 mul swap 100 add} def
/tick {tf moveto 0 15 rlineto} def

0 front { swap 9 add swap rear {over swap div 2 pick tick} forall drop } forall drop
stroke

newpath /Helvetica findfont 10 scalefont setfont

/ybase -2 def
/str 20 string def
/xjcenter {dup stringwidth pop 2 div neg 0 rmoveto} def
/xtick {dup ybase tf moveto 0 -2 rlineto 0 -10 rmoveto str cvs xjcenter show} def

[0.8 1 1.25 1.6 2 2.5 3.2 4] {xtick} forall
stroke
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