mtrace_count.m

function N = mtrace_count(T,A,t)
% Computes the count process sample, at resolution, for the marked trace
% (T,A).
 
time = sum(T(2:end));
periods = ceil(time / t);
C = unique(A);
 
N = zeros(periods,length(C));
Tcum = cumsum(T);
 
for i = 1:periods
    tstart = T(1) + (i-1) * t;
    tend = T(1) + i * t;
    for c = 1:length(C)
        % A == C(c), not A == c: c is the position in the class list, so any
        % label alphabet other than 1..length(C) was miscounted (all-zero
        % columns for labels outside that range).
        N(i,c) = sum( Tcum > tstart & Tcum <= tend & A == C(c) );
    end
end