Spike_threshold_PS(​trace,dt,win, win2, Fc,factordvdt)

Spike threshold detection alogrithm - Method I
This function calculates the spike threshold of a membrane potential
recording based on the method by Sekerli et al IEEE Trans Biom Eng
51(9): 1665-1672, 2004. In this paper they suggest several methods of
estimating threshold. Here we use the first method, which is based on
revealing the threshold in a phase plot of V versus the derivative
dVdt. The largest positive slope is an indication of the threshold.