function [spikes, voltage] = lifspikes(V0, E, tau, dt)
voltage = zeros(length(E), 1);
V = V0;
thresh = 1.0;
spikes = [];
for k = 1:length(E)
    voltage(k) = V;
    if V > thresh
        spikes = [spikes; k*dt];
        V = 0.0;
    end
    V = V + (-V+E(k))*dt/tau;
end
end