10. (C) Program for Negative binomial distribution.

10. (C) Program for Negative binomial distribution.

	function [expfre]=negbinfit(x, obsfre) n=length(x)-1;
	N=sum(obsfre);
	xbar=sum(x*obsfre')/N;
	rawmom2=sum(obsfre*(x^2)')/N;
	var=rawmom2-xbar^2;
	p=xbar/var;
	q=1-p;
	r=round(p*xbar/q);
	prob(1)=p^r;
	for i=1:n
	prob(i+1)=((i+1+r)/(i-1+1))*q*prob(i)
	end
	printf('expected frequencies\n');
	printf('------------------------------\n');
	expfre=round(prob*N);
	return(expfre);
	endfunction
	x=[0,1,2,3,4,5];
	obsfre=[12,50,100,80,45,5];
	negbinfit(x,obsfre)