Ramdom Walk

Rem http://en.wikipedia.org/wiki/Random_walk

clg

font "arial",20,100

graphsize 600,450

fastgraphics

stepsize=10

steps=0

For radius = 20 to 200 step 10

average=steps/10

rect 100+ radius*2,450-average,2,average

print "Radius="+radius;

print " Average number of steps="+average

steps=0

for trial = 1 to 10

x=0

y=0

color grey

rect 0,0,600,40

color yellow

circle 200,200,radius

color black

text 10,10,"Trial"+trial

while x^2+y^2 < radius^2

steps = steps+1

a=rand*2*pi

dx=cos(a)*stepsize

dy=sin(a)*stepsize

line 200+x,200+y,200+x+dx,200+y+dy

circle x+200,y+200,1

refresh

x=x+dx

y=y+dy

end while

next trial

next radius