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+#cython: boundscheck=False
+#cython: wraparound=False
+#cython: cdivision=True
+
+"""
+cython_distances.pyx
+
+cython implementation of the isi-, spike- and spike-sync distances
+
+Note: using cython memoryviews (e.g. double[:]) instead of ndarray objects
+improves the performance of spike_distance by a factor of 10!
+
+Copyright 2015, Mario Mulansky <mario.mulansky@gmx.net>
+
+Distributed under the BSD License
+
+"""
+
+"""
+To test whether things can be optimized: remove all yellow stuff
+in the html output::
+
+ cython -a cython_distances.pyx
+
+which gives::
+
+ cython_distances.html
+
+"""
+
+import numpy as np
+cimport numpy as np
+
+from libc.math cimport fabs
+from libc.math cimport fmax
+from libc.math cimport fmin
+
+DTYPE = np.float
+ctypedef np.float_t DTYPE_t
+
+
+############################################################
+# isi_distance_cython
+############################################################
+def isi_distance_cython(double[:] s1, double[:] s2,
+ double t_start, double t_end):
+
+ cdef double isi_value
+ cdef int index1, index2, index
+ cdef int N1, N2
+ cdef double nu1, nu2
+ cdef double last_t, curr_t, curr_isi
+ isi_value = 0.0
+ N1 = len(s1)
+ N2 = len(s2)
+
+ # first interspike interval - check if a spike exists at the start time
+ # and also account for spike trains with single spikes
+ if s1[0] > t_start:
+ # edge correction for the first interspike interval:
+ # take the maximum of the distance from the beginning to the first
+ # spike and the interval between the first two spikes.
+ # if there is only one spike, take the its distance to the beginning
+ nu1 = fmax(s1[0]-t_start, s1[1]-s1[0]) if N1 > 1 else s1[0]-t_start
+ index1 = -1
+ else:
+ # if the first spike is exactly at the start, take the distance
+ # to the next spike. If this is the only spike, take the distance to
+ # the end.
+ nu1 = s1[1]-s1[0] if N1 > 1 else t_end-s1[0]
+ index1 = 0
+
+ if s2[0] > t_start:
+ # edge correction as above
+ nu2 = fmax(s2[0]-t_start, s2[1]-s2[0]) if N2 > 1 else s2[0]-t_start
+ index2 = -1
+ else:
+ nu2 = s2[1]-s2[0] if N2 > 1 else t_end-s2[0]
+ index2 = 0
+
+ last_t = t_start
+ curr_isi = fabs(nu1-nu2)/fmax(nu1, nu2)
+ index = 1
+
+ with nogil: # release the interpreter to allow multithreading
+ while index1+index2 < N1+N2-2:
+ # check which spike is next, only if there are spikes left in 1
+ # next spike in 1 is earlier, or there are no spikes left in 2
+ if (index1 < N1-1) and ((index2 == N2-1) or
+ (s1[index1+1] < s2[index2+1])):
+ index1 += 1
+ curr_t = s1[index1]
+ if index1 < N1-1:
+ nu1 = s1[index1+1]-s1[index1]
+ else:
+ # edge correction for the last ISI:
+ # take the max of the distance of the last
+ # spike to the end and the previous ISI. If there was only
+ # one spike, always take the distance to the end.
+ nu1 = fmax(t_end-s1[index1], nu1) if N1 > 1 \
+ else t_end-s1[index1]
+ elif (index2 < N2-1) and ((index1 == N1-1) or
+ (s1[index1+1] > s2[index2+1])):
+ index2 += 1
+ curr_t = s2[index2]
+ if index2 < N2-1:
+ nu2 = s2[index2+1]-s2[index2]
+ else:
+ # edge correction for the end as above
+ nu2 = fmax(t_end-s2[index2], nu2) if N2 > 1 \
+ else t_end-s2[index2]
+ else: # s1[index1+1] == s2[index2+1]
+ index1 += 1
+ index2 += 1
+ curr_t = s1[index1]
+ if index1 < N1-1:
+ nu1 = s1[index1+1]-s1[index1]
+ else:
+ # edge correction for the end as above
+ nu1 = fmax(t_end-s1[index1], nu1) if N1 > 1 \
+ else t_end-s1[index1]
+ if index2 < N2-1:
+ nu2 = s2[index2+1]-s2[index2]
+ else:
+ # edge correction for the end as above
+ nu2 = fmax(t_end-s2[index2], nu2) if N2 > 1 \
+ else t_end-s2[index2]
+ # compute the corresponding isi-distance
+ isi_value += curr_isi * (curr_t - last_t)
+ curr_isi = fabs(nu1 - nu2) / fmax(nu1, nu2)
+ last_t = curr_t
+ index += 1
+
+ isi_value += curr_isi * (t_end - last_t)
+ # end nogil
+
+ return isi_value / (t_end-t_start)
+
+
+############################################################
+# get_min_dist_cython
+############################################################
+cdef inline double get_min_dist_cython(double spike_time,
+ double[:] spike_train,
+ # use memory view to ensure inlining
+ # np.ndarray[DTYPE_t,ndim=1] spike_train,
+ int N,
+ int start_index,
+ double t_start, double t_end) nogil:
+ """ Returns the minimal distance |spike_time - spike_train[i]|
+ with i>=start_index.
+ """
+ cdef double d, d_temp
+ # start with the distance to the start time
+ d = fabs(spike_time - t_start)
+ if start_index < 0:
+ start_index = 0
+ while start_index < N:
+ d_temp = fabs(spike_time - spike_train[start_index])
+ if d_temp > d:
+ return d
+ else:
+ d = d_temp
+ start_index += 1
+
+ # finally, check the distance to end time
+ d_temp = fabs(t_end - spike_time)
+ if d_temp > d:
+ return d
+ else:
+ return d_temp
+
+
+############################################################
+# isi_avrg_cython
+############################################################
+cdef inline double isi_avrg_cython(double isi1, double isi2) nogil:
+ return 0.5*(isi1+isi2)*(isi1+isi2)
+ # alternative definition to obtain <S> ~ 0.5 for Poisson spikes
+ # return 0.5*(isi1*isi1+isi2*isi2)
+ # another alternative definition without second normalization
+ # return 0.5*(isi1+isi2)
+
+
+############################################################
+# spike_distance_cython
+############################################################
+def spike_distance_cython(double[:] t1, double[:] t2,
+ double t_start, double t_end):
+
+ cdef int N1, N2, index1, index2, index
+ cdef double t_p1, t_f1, t_p2, t_f2, dt_p1, dt_p2, dt_f1, dt_f2
+ cdef double isi1, isi2, s1, s2
+ cdef double y_start, y_end, t_last, t_current, spike_value
+ cdef double[:] t_aux1 = np.empty(2)
+ cdef double[:] t_aux2 = np.empty(2)
+
+ spike_value = 0.0
+
+ N1 = len(t1)
+ N2 = len(t2)
+
+ # we can assume at least one spikes per spike train
+ assert N1 > 0
+ assert N2 > 0
+
+
+ with nogil: # release the interpreter to allow multithreading
+ t_last = t_start
+ # auxiliary spikes for edge correction - consistent with first/last ISI
+ t_aux1[0] = fmin(t_start, 2*t1[0]-t1[1]) if N1 > 1 else t_start
+ t_aux1[1] = fmax(t_end, 2*t1[N1-1]-t1[N1-2]) if N1 > 1 else t_end
+ t_aux2[0] = fmin(t_start, 2*t2[0]-t2[1]) if N2 > 1 else t_start
+ t_aux2[1] = fmax(t_end, 2*t2[N2-1]+-t2[N2-2]) if N2 > 1 else t_end
+ # print "aux spikes %.15f, %.15f ; %.15f, %.15f" % (t_aux1[0], t_aux1[1], t_aux2[0], t_aux2[1])
+ t_p1 = t_start if (t1[0] == t_start) else t_aux1[0]
+ t_p2 = t_start if (t2[0] == t_start) else t_aux2[0]
+ if t1[0] > t_start:
+ # dt_p1 = t2[0]-t_start
+ t_f1 = t1[0]
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, 0, t_aux2[0], t_aux2[1])
+ isi1 = fmax(t_f1-t_start, t1[1]-t1[0]) if N1 > 1 else t_f1-t_start
+ dt_p1 = dt_f1
+ # s1 = dt_p1*(t_f1-t_start)/isi1
+ s1 = dt_p1
+ index1 = -1
+ else: # t1[0] == t_start
+ t_f1 = t1[1] if N1 > 1 else t_end
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, 0, t_aux2[0], t_aux2[1])
+ dt_p1 = get_min_dist_cython(t_p1, t2, N2, 0, t_aux2[0], t_aux2[1])
+ isi1 = t_f1-t1[0]
+ s1 = dt_p1
+ index1 = 0
+ if t2[0] > t_start:
+ # dt_p1 = t2[0]-t_start
+ t_f2 = t2[0]
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, 0, t_aux1[0], t_aux1[1])
+ dt_p2 = dt_f2
+ isi2 = fmax(t_f2-t_start, t2[1]-t2[0]) if N2 > 1 else t_f2-t_start
+ # s2 = dt_p2*(t_f2-t_start)/isi2
+ s2 = dt_p2
+ index2 = -1
+ else: # t2[0] == t_start
+ t_f2 = t2[1] if N2 > 1 else t_end
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, 0, t_aux1[0], t_aux1[1])
+ # dt_p2 = t_start-t_p1 # 0.0
+ dt_p2 = get_min_dist_cython(t_p2, t1, N1, 0, t_aux1[0], t_aux1[1])
+ isi2 = t_f2-t2[0]
+ s2 = dt_p2
+ index2 = 0
+
+ y_start = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ # y_start = (s1 + s2) / isi_avrg_cython(isi1, isi2)
+ index = 1
+
+ while index1+index2 < N1+N2-2:
+ # print(index, index1, index2)
+ if (index1 < N1-1) and (t_f1 < t_f2 or index2 == N2-1):
+ index1 += 1
+ # first calculate the previous interval end value
+ s1 = dt_f1*(t_f1-t_p1) / isi1
+ # the previous time now was the following time before:
+ dt_p1 = dt_f1
+ t_p1 = t_f1 # t_p1 contains the current time point
+ # get the next time
+ if index1 < N1-1:
+ t_f1 = t1[index1+1]
+ else:
+ t_f1 = t_aux1[1]
+ t_curr = t_p1
+ s2 = (dt_p2*(t_f2-t_p1) + dt_f2*(t_p1-t_p2)) / isi2
+ y_end = (s1*isi2 + s2*isi1)/isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ # y_end = (s1 + s2) / isi_avrg_cython(isi1, isi2)
+
+ spike_value += 0.5*(y_start + y_end) * (t_curr - t_last)
+
+ # now the next interval start value
+ if index1 < N1-1:
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, index2,
+ t_aux2[0], t_aux2[1])
+ isi1 = t_f1-t_p1
+ s1 = dt_p1
+ else:
+ dt_f1 = dt_p1
+ isi1 = fmax(t_end-t1[N1-1], t1[N1-1]-t1[N1-2]) if N1 > 1 \
+ else t_end-t1[N1-1]
+ # s1 needs adjustment due to change of isi1
+ # s1 = dt_p1*(t_end-t1[N1-1])/isi1
+ # Eero's correction: no adjustment
+ s1 = dt_p1
+ # s2 is the same as above, thus we can compute y2 immediately
+ y_start = (s1*isi2 + s2*isi1)/isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ # y_start = (s1 + s2) / isi_avrg_cython(isi1, isi2)
+ elif (index2 < N2-1) and (t_f1 > t_f2 or index1 == N1-1):
+ index2 += 1
+ # first calculate the previous interval end value
+ s2 = dt_f2*(t_f2-t_p2) / isi2
+ # the previous time now was the following time before:
+ dt_p2 = dt_f2
+ t_p2 = t_f2 # t_p2 contains the current time point
+ # get the next time
+ if index2 < N2-1:
+ t_f2 = t2[index2+1]
+ else:
+ t_f2 = t_aux2[1]
+ t_curr = t_p2
+ s1 = (dt_p1*(t_f1-t_p2) + dt_f1*(t_p2-t_p1)) / isi1
+ y_end = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ # y_end = (s1 + s2) / isi_avrg_cython(isi1, isi2)
+
+ spike_value += 0.5*(y_start + y_end) * (t_curr - t_last)
+
+ # now the next interval start value
+ if index2 < N2-1:
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, index1,
+ t_aux1[0], t_aux1[1])
+ isi2 = t_f2-t_p2
+ s2 = dt_p2
+ else:
+ dt_f2 = dt_p2
+ isi2 = fmax(t_end-t2[N2-1], t2[N2-1]-t2[N2-2]) if N2 > 1 \
+ else t_end-t2[N2-1]
+ # s2 needs adjustment due to change of isi2
+ # s2 = dt_p2*(t_end-t2[N2-1])/isi2
+ # Eero's correction: no adjustment
+ s2 = dt_p2
+ # s1 is the same as above, thus we can compute y2 immediately
+ y_start = (s1*isi2 + s2*isi1)/isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ # y_start = (s1 + s2) / isi_avrg_cython(isi1, isi2)
+
+ else: # t_f1 == t_f2 - generate only one event
+ index1 += 1
+ index2 += 1
+ t_p1 = t_f1
+ t_p2 = t_f2
+ dt_p1 = 0.0
+ dt_p2 = 0.0
+ t_curr = t_f1
+ y_end = 0.0
+ spike_value += 0.5*(y_start + y_end) * (t_curr - t_last)
+ y_start = 0.0
+ if index1 < N1-1:
+ t_f1 = t1[index1+1]
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, index2,
+ t_aux2[0], t_aux2[1])
+ isi1 = t_f1 - t_p1
+ else:
+ t_f1 = t_aux1[1]
+ dt_f1 = dt_p1
+ isi1 = fmax(t_end-t1[N1-1], t1[N1-1]-t1[N1-2]) if N1 > 1 \
+ else t_end-t1[N1-1]
+ if index2 < N2-1:
+ t_f2 = t2[index2+1]
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, index1,
+ t_aux1[0], t_aux1[1])
+ isi2 = t_f2 - t_p2
+ else:
+ t_f2 = t_aux2[1]
+ dt_f2 = dt_p2
+ isi2 = fmax(t_end-t2[N2-1], t2[N2-1]-t2[N2-2]) if N2 > 1 \
+ else t_end-t2[N2-1]
+ index += 1
+ t_last = t_curr
+ # isi1 = max(t_end-t1[N1-1], t1[N1-1]-t1[N1-2])
+ # isi2 = max(t_end-t2[N2-1], t2[N2-1]-t2[N2-2])
+ s1 = dt_f1 # *(t_end-t1[N1-1])/isi1
+ s2 = dt_f2 # *(t_end-t2[N2-1])/isi2
+ y_end = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ # y_end = (s1 + s2) / isi_avrg_cython(isi1, isi2)
+
+ spike_value += 0.5*(y_start + y_end) * (t_end - t_last)
+ # end nogil
+
+ # use only the data added above
+ # could be less than original length due to equal spike times
+ return spike_value / (t_end-t_start)
+
+
+############################################################
+# isi_avrg_rf_cython
+############################################################
+cdef inline double isi_avrg_rf_cython(double isi1, double isi2) nogil:
+ # rate free version
+ return (isi1+isi2)
+
+
+############################################################
+# spike_distance_rf_cython
+############################################################
+def spike_distance_rf_cython(double[:] t1, double[:] t2,
+ double t_start, double t_end):
+
+ cdef int N1, N2, index1, index2, index
+ cdef double t_p1, t_f1, t_p2, t_f2, dt_p1, dt_p2, dt_f1, dt_f2
+ cdef double isi1, isi2, s1, s2
+ cdef double y_start, y_end, t_last, t_current, spike_value
+
+ spike_value = 0.0
+
+ N1 = len(t1)
+ N2 = len(t2)
+
+ with nogil: # release the interpreter to allow multithreading
+ t_last = t_start
+ t_p1 = t_start
+ t_p2 = t_start
+ if t1[0] > t_start:
+ # dt_p1 = t2[0]-t_start
+ t_f1 = t1[0]
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, 0, t_start, t_end)
+ isi1 = fmax(t_f1-t_start, t1[1]-t1[0])
+ dt_p1 = dt_f1
+ s1 = dt_p1*(t_f1-t_start)/isi1
+ index1 = -1
+ else:
+ t_f1 = t1[1]
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, 0, t_start, t_end)
+ dt_p1 = 0.0
+ isi1 = t1[1]-t1[0]
+ s1 = dt_p1
+ index1 = 0
+ if t2[0] > t_start:
+ # dt_p1 = t2[0]-t_start
+ t_f2 = t2[0]
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, 0, t_start, t_end)
+ dt_p2 = dt_f2
+ isi2 = fmax(t_f2-t_start, t2[1]-t2[0])
+ s2 = dt_p2*(t_f2-t_start)/isi2
+ index2 = -1
+ else:
+ t_f2 = t2[1]
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, 0, t_start, t_end)
+ dt_p2 = 0.0
+ isi2 = t2[1]-t2[0]
+ s2 = dt_p2
+ index2 = 0
+
+ # y_start = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ y_start = (s1 + s2) / isi_avrg_rf_cython(isi1, isi2)
+ index = 1
+
+ while index1+index2 < N1+N2-2:
+ # print(index, index1, index2)
+ if (index1 < N1-1) and (t_f1 < t_f2 or index2 == N2-1):
+ index1 += 1
+ # first calculate the previous interval end value
+ s1 = dt_f1*(t_f1-t_p1) / isi1
+ # the previous time now was the following time before:
+ dt_p1 = dt_f1
+ t_p1 = t_f1 # t_p1 contains the current time point
+ # get the next time
+ if index1 < N1-1:
+ t_f1 = t1[index1+1]
+ else:
+ t_f1 = t_end
+ t_curr = t_p1
+ s2 = (dt_p2*(t_f2-t_p1) + dt_f2*(t_p1-t_p2)) / isi2
+ # y_end = (s1*isi2 + s2*isi1)/isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ y_end = (s1 + s2) / isi_avrg_rf_cython(isi1, isi2)
+
+ spike_value += 0.5*(y_start + y_end) * (t_curr - t_last)
+
+ # now the next interval start value
+ if index1 < N1-1:
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, index2,
+ t_start, t_end)
+ isi1 = t_f1-t_p1
+ s1 = dt_p1
+ else:
+ dt_f1 = dt_p1
+ isi1 = fmax(t_end-t1[N1-1], t1[N1-1]-t1[N1-2])
+ # s1 needs adjustment due to change of isi1
+ s1 = dt_p1*(t_end-t1[N1-1])/isi1
+ # s2 is the same as above, thus we can compute y2 immediately
+ # y_start = (s1*isi2 + s2*isi1)/isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ y_start = (s1 + s2) / isi_avrg_rf_cython(isi1, isi2)
+ elif (index2 < N2-1) and (t_f1 > t_f2 or index1 == N1-1):
+ index2 += 1
+ # first calculate the previous interval end value
+ s2 = dt_f2*(t_f2-t_p2) / isi2
+ # the previous time now was the following time before:
+ dt_p2 = dt_f2
+ t_p2 = t_f2 # t_p2 contains the current time point
+ # get the next time
+ if index2 < N2-1:
+ t_f2 = t2[index2+1]
+ else:
+ t_f2 = t_end
+ t_curr = t_p2
+ s1 = (dt_p1*(t_f1-t_p2) + dt_f1*(t_p2-t_p1)) / isi1
+ # y_end = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ y_end = (s1 + s2) / isi_avrg_rf_cython(isi1, isi2)
+
+ spike_value += 0.5*(y_start + y_end) * (t_curr - t_last)
+
+ # now the next interval start value
+ if index2 < N2-1:
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, index1,
+ t_start, t_end)
+ isi2 = t_f2-t_p2
+ s2 = dt_p2
+ else:
+ dt_f2 = dt_p2
+ isi2 = fmax(t_end-t2[N2-1], t2[N2-1]-t2[N2-2])
+ # s2 needs adjustment due to change of isi2
+ s2 = dt_p2*(t_end-t2[N2-1])/isi2
+ # s1 is the same as above, thus we can compute y2 immediately
+ # y_start = (s1*isi2 + s2*isi1)/isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ y_start = (s1 + s2) / isi_avrg_rf_cython(isi1, isi2)
+
+ else: # t_f1 == t_f2 - generate only one event
+ index1 += 1
+ index2 += 1
+ t_p1 = t_f1
+ t_p2 = t_f2
+ dt_p1 = 0.0
+ dt_p2 = 0.0
+ t_curr = t_f1
+ y_end = 0.0
+ spike_value += 0.5*(y_start + y_end) * (t_curr - t_last)
+ y_start = 0.0
+ if index1 < N1-1:
+ t_f1 = t1[index1+1]
+ dt_f1 = get_min_dist_cython(t_f1, t2, N2, index2,
+ t_start, t_end)
+ isi1 = t_f1 - t_p1
+ else:
+ t_f1 = t_end
+ dt_f1 = dt_p1
+ isi1 = fmax(t_end-t1[N1-1], t1[N1-1]-t1[N1-2])
+ if index2 < N2-1:
+ t_f2 = t2[index2+1]
+ dt_f2 = get_min_dist_cython(t_f2, t1, N1, index1,
+ t_start, t_end)
+ isi2 = t_f2 - t_p2
+ else:
+ t_f2 = t_end
+ dt_f2 = dt_p2
+ isi2 = fmax(t_end-t2[N2-1], t2[N2-1]-t2[N2-2])
+ index += 1
+ t_last = t_curr
+ # isi1 = max(t_end-t1[N1-1], t1[N1-1]-t1[N1-2])
+ # isi2 = max(t_end-t2[N2-1], t2[N2-1]-t2[N2-2])
+ s1 = dt_f1*(t_end-t1[N1-1])/isi1
+ s2 = dt_f2*(t_end-t2[N2-1])/isi2
+ # y_end = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, isi2)
+ # alternative definition without second normalization
+ y_end = (s1 + s2) / isi_avrg_rf_cython(isi1, isi2)
+
+ spike_value += 0.5*(y_start + y_end) * (t_end - t_last)
+ # end nogil
+
+ # use only the data added above
+ # could be less than original length due to equal spike times
+ return spike_value / (t_end-t_start)
+
+
+
+############################################################
+# get_tau
+############################################################
+cdef inline double get_tau(double[:] spikes1, double[:] spikes2,
+ int i, int j, double interval, double max_tau):
+ cdef double m = interval # use interval length as initial tau
+ cdef int N1 = spikes1.shape[0]-1 # len(spikes1)-1
+ cdef int N2 = spikes2.shape[0]-1 # len(spikes2)-1
+ if i < N1 and i > -1:
+ m = fmin(m, spikes1[i+1]-spikes1[i])
+ if j < N2 and j > -1:
+ m = fmin(m, spikes2[j+1]-spikes2[j])
+ if i > 0:
+ m = fmin(m, spikes1[i]-spikes1[i-1])
+ if j > 0:
+ m = fmin(m, spikes2[j]-spikes2[j-1])
+ m *= 0.5
+ if max_tau > 0.0:
+ m = fmin(m, max_tau)
+ return m
+
+
+############################################################
+# coincidence_value_cython
+############################################################
+def coincidence_value_cython(double[:] spikes1, double[:] spikes2,
+ double t_start, double t_end, double max_tau):
+
+ cdef int N1 = len(spikes1)
+ cdef int N2 = len(spikes2)
+ cdef int i = -1
+ cdef int j = -1
+ cdef double coinc = 0.0
+ cdef double mp = 0.0
+ cdef double interval = t_end - t_start
+ cdef double tau
+ while i + j < N1 + N2 - 2:
+ if (i < N1-1) and (j == N2-1 or spikes1[i+1] < spikes2[j+1]):
+ i += 1
+ mp += 1
+ tau = get_tau(spikes1, spikes2, i, j, interval, max_tau)
+ if j > -1 and spikes1[i]-spikes2[j] < tau:
+ # coincidence between the current spike and the previous spike
+ # both get marked with 1
+ coinc += 2
+ elif (j < N2-1) and (i == N1-1 or spikes1[i+1] > spikes2[j+1]):
+ j += 1
+ mp += 1
+ tau = get_tau(spikes1, spikes2, i, j, interval, max_tau)
+ if i > -1 and spikes2[j]-spikes1[i] < tau:
+ # coincidence between the current spike and the previous spike
+ # both get marked with 1
+ coinc += 2
+ else: # spikes1[i+1] = spikes2[j+1]
+ # advance in both spike trains
+ j += 1
+ i += 1
+ # add only one event, but with coincidence 2 and multiplicity 2
+ mp += 2
+ coinc += 2
+
+ return coinc, mp