MAP

function [cv, cvTimes, allTimeStamps, allISIs]=  UTIL_CV(earObject, dt, timeStep)

% UTIL_CV computes coefficient of variation for multiple spike trains

% earObject must be logical 0/1.  Each row is a separate run

% CV is computed for successive time regions specified by timeStep

if ~islogical(earObject),error('UTIL_CV: input is not logical/ spikes'), end

[rows cols]=size(earObject);

totalDuration=cols*dt;

if nargin<3, timeStep=totalDuration/5; end

% identify all intervals

allISIs=[]; allTimeStamps=[];

for i=1:rows

    temp=find(earObject(i,:))*dt;    % find spikes

    isi{i}=diff(temp);                      % find ISIs

    timeStamps{i}=temp(2:end); % time of isi is time of second spike

    allISIs=[allISIs isi{i}];

    allTimeStamps=[allTimeStamps timeStamps{i}];

end

count=0;

cvTimes=0: timeStep:totalDuration-timeStep; % bin edges

for t= cvTimes

    % sort ISIs according to when they happened

    idx=find(allTimeStamps>t & allTimeStamps<=t+timeStep);

    count=count+1;

    if ~isempty(allISIs(idx))

        cv(count)=std(allISIs(idx))/mean(allISIs(idx));

    else

        cv(count)=0;

    end

end