% Return a 'jittered' version of the process
% Pin.  isirand is a function handle that returns
% random number from the jitter distribution.
% dt is the binsize of the (to determine units).
% Pout=jitter(Pin,jrand,dt)
% To impose a Gaussian (normally distributed) 
% jitter, you might call:
%      pout=jitter(pin,@randn,.1);
% For more examples using function handles in 
% this situation, see the notes for renewal.m

function Pout=jitter(Pin,isirand,dt);


% Initialize Pout
n=numel(Pin);
Pout=zeros(1,n);


% Get a representation of Pin 
% in terms of spike times
s=find(Pin);


% Fill Pout making sure not to
% use indices that are out of bounds
for i=1:numel(s)
    J=round(s(i)+feval(isirand)/dt);
    if J>0 && J<n
        Pout(J)=Pout(J)+1;
    end
end