From 8841138b74242ed9eb77c972c76e9a617778a79a Mon Sep 17 00:00:00 2001 From: Mario Mulansky Date: Wed, 13 May 2015 18:19:02 +0200 Subject: pwc function now returns intermediate value at exact spike times --- pyspike/PieceWiseConstFunc.py | 35 +++++++++++++++++++++++++++-------- 1 file changed, 27 insertions(+), 8 deletions(-) (limited to 'pyspike/PieceWiseConstFunc.py') diff --git a/pyspike/PieceWiseConstFunc.py b/pyspike/PieceWiseConstFunc.py index cf64e58..dea1a56 100644 --- a/pyspike/PieceWiseConstFunc.py +++ b/pyspike/PieceWiseConstFunc.py @@ -37,16 +37,35 @@ class PieceWiseConstFunc(object): "Invalid time: " + str(t) ind = np.searchsorted(self.x, t, side='right') - # correct the cases t == x[0], t == x[-1] - try: + if isinstance(t, collections.Sequence): + # t is a sequence of values + # correct the cases t == x[0], t == x[-1] ind[ind == 0] = 1 ind[ind == len(self.x)] = len(self.x)-1 - except TypeError: - if ind == 0: - ind = 1 - if ind == len(self.x): - ind = len(self.x)-1 - return self.y[ind-1] + value = self.y[ind-1] + # correct the values at exact spike times: there the value should + # be the at half of the step + # obtain the 'left' side indices for t + ind_l = np.searchsorted(self.x, t, side='left') + # if left and right side indices differ, the time t has to appear + # in self.x + ind_at_spike = ind[np.logical_and(np.logical_and(ind != ind_l, + ind > 1), + ind < len(self.x))] + value[ind_at_spike] = 0.5 * (self.y[ind_at_spike-1] + + self.y[ind_at_spike-2]) + return value + else: + # specific check for interval edges + if t == self.x[0]: + return self.y[0] + if t == self.x[-1]: + return self.y[-1] + # check if we are on any other exact spike time + if sum(self.x == t) > 0: + # use the middle of the left and right ISI value + return 0.5 * (self.y[ind-1] + self.y[ind-2]) + return self.y[ind-1] def copy(self): """ Returns a copy of itself -- cgit v1.2.3