automatic_replot = 0 ;
				# Demonstrate the central limit theorem
				# for any discrete distribution over integers.

				# To use this, run octave, then type doit

				# Define x_n is a random variable from:
				# P(x) = p(0),p(1),p(2)....p(k)
p=[ 0.5, 0.5 ];
p=[ 0.9 , 0.1 ];
p=[ 0.5 , 0, 0,0, 0.3 , 0.1 ,0,0,  0.1 ];
				# z= sum(x_n);
				# compute P(z) = p*p*p*p .... *p .
				# where "*" denotes convolution.
gset nokey
clear y ;
Nmax = 2500;

				# Find prob distbn of r, the number of
				# heads,
				# given N tosses
y = p ;
for N=1:Nmax  # loop over N=1...Nmax

				# to tell gnuplot numbers that octave
				# knows,
				# we have to build a string, then
				# evaluate it.
  command = sprintf(" gset yrange [0: %f]", max(y) )  ;
  eval(command);

				# let's set the xrange in a smart way.
  s = size(y) ;
  command = sprintf(" gset xrange [0: %d]", s(2)-1  )  ;
  eval(command);

				# add a nice title
  command = sprintf("   gset title \"%d\" " , N )  ;
  eval(command);
				# do the plot!
  gplot y' w impulse 3
  if( N<35 )
    ans= input("ready?") ; 
  endif
  y= conv(y,p);  # do the convolution of y with p
endfor