function [ rate ] = firingrate(spikes, t0, t1)
% compute the firing rate from spikes between t0 and t1

rates = zeros(length(spikes), 1);
for k = 1:length(spikes)
    spiketimes = spikes{k};
    rates(k) = length(spiketimes((spiketimes>=t0)&(spiketimes<=t1)))/(t1-t0);
end
rate = mean(rates);
end