function plotfanofactor(spikes, wmin, wmax)
% Compute and plot Fano factor as a function of window size.
%
% Arguments:
%   spikes: a cell array of vectors of spike times in seconds
%   wmin: minimum window size in seconds
%   wmax: maximum window size in seconds
    windows = logspace(log10(wmin), log10(wmax), 100);
    mc = zeros(1, length(windows));
    vc = zeros(1, length(windows));
    for k = 1:length(windows)
        w = windows(k);
        n = counts(spikes, w);
        mc(k) = mean(n);
        vc(k) = var(n);
    end
    
    subplot(1, 2, 1);
    scatter(mc, vc, 'filled');
    xlabel('Mean count');
    ylabel('Count variance');

    subplot(1, 2, 2);
    scatter(1000.0*windows, vc ./ mc, 'filled');
    xlabel('Window [ms]');
    ylabel('Fano factor');
    xlim(1000.0*[windows(1) windows(end)])
    ylim([0.0 1.1]);
    set(gca, 'XScale', 'log');
end