Happy PI Day to all you Logo Fanatics!

The message below is being cross-posted from the LogoForum. Please
reply here at comp.lang.logo and it will be crossposted back to the
LogoForum. The original author of this message is "Dale Reed"
<dale-reed@worldnet.nospam.att.net>.


to aaa :totdots
; LogoForum, Tue Nov 2, 2004 3:52 pm
; Message 10143
; For just one run try: erns aaa 10000
; For many runs try: main 1000 10
cs ht pu
setlabelfont[
[Courier New] -24 0 0 800 0 0 0 177 3 2 1 57]
rt 90
setxy -120 300
setpc [0 0 0]
label [Monte Carlo Method to approximate PI]
setpensize [3 3]
repeat 300[setxy -300+repcount -450+3.14159*100 setpc [0 0 0] pd fd 400
pu]
setxy -430 -120 label "3.14159
make "radius 250
make "M 0
make "pie 0
make "N 0
make "runtime 0
make "start timemilli
dotting
timer
(print "PI "= ie " " "time "= :runtime)
setxy -170 -40
label "PI=
setxy 0 -40
label "counts=
setxy 310 -40
label "seconds
setactivearea [-250 -100 450 300]
;gifsave "MonteCarlo.gif
end

to counter
localmake "display.step modulo :N 50
timer
if :display.step = 0 [
;Count the calculated PI
setxy -120 -40
rubout
setpc [0 0 0]
label ie
; Count the Total Runtime
setxy 105 -40
rubout
setpc [0 0 0]
label :N
setxy 210 -40
label :runtime
]
end

to dot
ifelse (distance [0 0]) > :radius [ setpixel [0 0 255]] [setpixel [255 0
0]
make "M :M+1]
make "pie 4 * :M / :N
end

to dotting
repeat :totdots[setxy random :radius+1 random :radius+1 make "N repcount
dot counter plot ]
end

to main :totdots :number.of.runs
repeat :number.of.runs[aaa :totdots wait 100]
end

to plot
setpc [0 155 0] setpensize [2 2]
setxy -300+:N/10 -450+100*(ie)
pd fd 1 pu
end

to rubout
pd
setpc [25 255 255]
setpensize [40 40]
bk 80 fd 400 bk 320
pu
end

to timer
make "runtime (timemilli - :start)/1000
end
---
$ dale-reed@worldnet.att.net Seattle, Washington $