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Diffstat (limited to 'pyspike/cython/cython_profiles.pyx')
| -rw-r--r-- | pyspike/cython/cython_profiles.pyx | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/pyspike/cython/cython_profiles.pyx b/pyspike/cython/cython_profiles.pyx new file mode 100644 index 0000000..f9893eb --- /dev/null +++ b/pyspike/cython/cython_profiles.pyx @@ -0,0 +1,428 @@ +#cython: boundscheck=False +#cython: wraparound=False +#cython: cdivision=True + +""" +cython_profiles.pyx + +cython implementation of the isi-, spike- and spike-sync profiles + +Note: using cython memoryviews (e.g. double[:]) instead of ndarray objects +improves the performance of spike_distance by a factor of 10! + +Copyright 2014-2015, 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_profiles.pyx + +which gives:: + + cython_profiles.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_profile_cython +############################################################ +def isi_profile_cython(double[:] s1, double[:] s2, + double t_start, double t_end): + + cdef double[:] spike_events + cdef double[:] isi_values + cdef int index1, index2, index + cdef int N1, N2 + cdef double nu1, nu2 + N1 = len(s1) + N2 = len(s2) + + spike_events = np.empty(N1+N2+2) + # the values have one entry less as they are defined at the intervals + isi_values = np.empty(N1+N2+1) + + # first x-value of the profile + spike_events[0] = t_start + + # first interspike interval - check if a spike exists at the start time + if s1[0] > t_start: + # edge correction + nu1 = fmax(s1[0]-t_start, s1[1]-s1[0]) + index1 = -1 + else: + nu1 = s1[1]-s1[0] + index1 = 0 + + if s2[0] > t_start: + # edge correction + nu2 = fmax(s2[0]-t_start, s2[1]-s2[0]) + index2 = -1 + else: + nu2 = s2[1]-s2[0] + index2 = 0 + + isi_values[0] = 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 + spike_events[index] = s1[index1] + if index1 < N1-1: + nu1 = s1[index1+1]-s1[index1] + else: + # edge correction + nu1 = fmax(t_end-s1[index1], nu1) + elif (index2 < N2-1) and ((index1 == N1-1) or + (s1[index1+1] > s2[index2+1])): + index2 += 1 + spike_events[index] = s2[index2] + if index2 < N2-1: + nu2 = s2[index2+1]-s2[index2] + else: + # edge correction + nu2 = fmax(t_end-s2[index2], nu2) + else: # s1[index1+1] == s2[index2+1] + index1 += 1 + index2 += 1 + spike_events[index] = s1[index1] + if index1 < N1-1: + nu1 = s1[index1+1]-s1[index1] + else: + # edge correction + nu1 = fmax(t_end-s1[index1], nu1) + if index2 < N2-1: + nu2 = s2[index2+1]-s2[index2] + else: + # edge correction + nu2 = fmax(t_end-s2[index2], nu2) + # compute the corresponding isi-distance + isi_values[index] = fabs(nu1 - nu2) / fmax(nu1, nu2) + index += 1 + # the last event is the interval end + if spike_events[index-1] == t_end: + index -= 1 + else: + spike_events[index] = t_end + # end nogil + + return spike_events[:index+1], isi_values[:index] + + +############################################################ +# 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) + + +############################################################ +# spike_profile_cython +############################################################ +def spike_profile_cython(double[:] t1, double[:] t2, + double t_start, double t_end): + + cdef double[:] spike_events + cdef double[:] y_starts + cdef double[:] y_ends + + 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 + + N1 = len(t1) + N2 = len(t2) + + spike_events = np.empty(N1+N2+2) + + y_starts = np.empty(len(spike_events)-1) + y_ends = np.empty(len(spike_events)-1) + + with nogil: # release the interpreter to allow multithreading + spike_events[0] = 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_starts[0] = (s1*isi2 + s2*isi1) / 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_end + spike_events[index] = t_p1 + s2 = (dt_p2*(t_f2-t_p1) + dt_f2*(t_p1-t_p2)) / isi2 + y_ends[index-1] = (s1*isi2 + s2*isi1)/isi_avrg_cython(isi1, + isi2) + # 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_starts[index] = (s1*isi2 + s2*isi1)/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_end + spike_events[index] = t_p2 + s1 = (dt_p1*(t_f1-t_p2) + dt_f1*(t_p2-t_p1)) / isi1 + y_ends[index-1] = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, + isi2) + # 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 + # s2 is the same as above, thus we can compute y2 immediately + y_starts[index] = (s1*isi2 + s2*isi1)/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 + spike_events[index] = t_f1 + y_ends[index-1] = 0.0 + y_starts[index] = 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 + # the last event is the interval end + if spike_events[index-1] == t_end: + index -= 1 + else: + spike_events[index] = t_end + # the ending value of the last interval + 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_ends[index-1] = (s1*isi2 + s2*isi1) / isi_avrg_cython(isi1, isi2) + # end nogil + + # use only the data added above + # could be less than original length due to equal spike times + return spike_events[:index+1], y_starts[:index], y_ends[:index] + + + +############################################################ +# 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 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_profile_cython +############################################################ +def coincidence_profile_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 int n = 0 + cdef double[:] st = np.zeros(N1 + N2 + 2) # spike times + cdef double[:] c = np.zeros(N1 + N2 + 2) # coincidences + cdef double[:] mp = np.ones(N1 + N2 + 2) # multiplicity + 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 + n += 1 + tau = get_tau(spikes1, spikes2, i, j, interval, max_tau) + st[n] = spikes1[i] + if j > -1 and spikes1[i]-spikes2[j] < tau: + # coincidence between the current spike and the previous spike + # both get marked with 1 + c[n] = 1 + c[n-1] = 1 + elif (j < N2-1) and (i == N1-1 or spikes1[i+1] > spikes2[j+1]): + j += 1 + n += 1 + tau = get_tau(spikes1, spikes2, i, j, interval, max_tau) + st[n] = spikes2[j] + if i > -1 and spikes2[j]-spikes1[i] < tau: + # coincidence between the current spike and the previous spike + # both get marked with 1 + c[n] = 1 + c[n-1] = 1 + else: # spikes1[i+1] = spikes2[j+1] + # advance in both spike trains + j += 1 + i += 1 + n += 1 + # add only one event, but with coincidence 2 and multiplicity 2 + st[n] = spikes1[i] + c[n] = 2 + mp[n] = 2 + + st = st[:n+2] + c = c[:n+2] + mp = mp[:n+2] + + st[0] = t_start + st[len(st)-1] = t_end + if N1 + N2 > 0: + c[0] = c[1] + c[len(c)-1] = c[len(c)-2] + mp[0] = mp[1] + mp[len(mp)-1] = mp[len(mp)-2] + else: + c[0] = 1 + c[1] = 1 + + return st, c, mp |