Computer Assignment 2 - Stockholms universitet

ans =0.2001for N = 10, p = 0.3 and k = 4.The corresponding value of the cumulative distribution function( )k∑ NΦ(k, N, p) = p i (1 − p) N−ii=0ican just as easily be obtained using binocdf(k,N,p) as>> binocdf(4,10,0.3)ans =0.8497If you do not have access to the statistics toolbox, you can still calculate the cumulativedistribution function as>> for i=0:4p(i+1)=nchoosek(10,i)*power(0.3,i)*power(1-0.3,10-i);end>> sum(p)ans =0.8497where the function nchoosek yields the binomial coefficient ( )10i . Since it is often necessaryto make these calculations several times when analysing properties of options, you cancreate the file binocdf.m, placed in the directory where you work with Matlab, with thecontentfunction y=binocdf(k,N,p)f(1)=power(1-p,N);for i=1:Nf(i+1)=f(i)*(N-i+1)/i*p/(1-p);endfor i=1:length(k)y(i)=cumsum(f(k(i)+1));end(This is similar to the implementation in Matlab, where you can use a vector x as anargument.)2