```Date: Jan 13, 2013 3:55 PM
Author: Derek Goring
Subject: Re: PDF to CDF in MATLAB

On Monday, January 14, 2013 8:40:09 AM UTC+13, Hemming  wrote:> Hi!> > Im trying to extract a scattering angle for a photon using the Klein-Nishina scattering angle distribution (KN in the code) and for this I need the CDF (of KN) to be able to use the Monte Carlo method when that is achieved. All i've managed so far is to plot the PDF between 0 degrees and Pi to see that it looks alright, and that it has that "peanut shape". Ive tried to use the built in CDF function but it seems very slow.> > > > E_gamma=0.140;> > alpha=0.511;> > P=zeros(3142,1);> > KN_matrix=zeros(3142, 1);> > > > for  k=1:3142  > > j=(k-1)/1000;> > PE=1/(1+((E_gamma/alpha)*(1-cos(j))));> > KN=(PE^2*(PE+(1/PE)-1+(cos(j))^2))/2;> > KN_matrix(k,1)=(KN);> > plot(j,KN_matrix(k,1)) > > hold on> > end> > > > Thanks!> > axis equalInstead of plotting in a loop, define vectors:j=[0:3141]'/1000;PE=1/(1+((E_gamma/alpha)*(1-cos(j))));KN_matrix=(PE.^2.*(PE+(1./PE)-1+(cos(j)).^2))/2;plot(j,KN_matrix)Notice the dots before the operators to get element-by-element multiplication, exponentiation, etc.
```