diff options
Diffstat (limited to 'pyspike/spikes.py')
| -rw-r--r-- | pyspike/spikes.py | 129 |
1 files changed, 41 insertions, 88 deletions
diff --git a/pyspike/spikes.py b/pyspike/spikes.py index 9d7d6f4..35d8533 100644 --- a/pyspike/spikes.py +++ b/pyspike/spikes.py @@ -1,102 +1,57 @@ -""" spikes.py - -Module containing several function to load and transform spike trains - -Copyright 2014, Mario Mulansky <mario.mulansky@gmx.net> - -Distributed under the BSD License -""" +# Module containing several function to load and transform spike trains +# Copyright 2014, Mario Mulansky <mario.mulansky@gmx.net> +# Distributed under the BSD License import numpy as np - - -############################################################ -# add_auxiliary_spikes -############################################################ -def add_auxiliary_spikes(spike_train, time_interval): - """ Adds spikes at the beginning and end of the given time interval. - - :param spike_train: ordered array of spike times - :param time_interval: A pair (T_start, T_end) of values representing the - start and end time of the spike train measurement or - a single value representing the end time, the T_start - is then assuemd as 0. Auxiliary spikes will be added - to the spike train at the beginning and end of this - interval, if they are not yet present. - :type time_interval: pair of doubles or double - :returns: spike train with additional spikes at T_start and T_end. - - """ - try: - T_start = time_interval[0] - T_end = time_interval[1] - except: - T_start = 0 - T_end = time_interval - - assert spike_train[0] >= T_start, \ - "Spike train has events before the given start time" - assert spike_train[-1] <= T_end, \ - "Spike train has events after the given end time" - if spike_train[0] != T_start: - spike_train = np.insert(spike_train, 0, T_start) - if spike_train[-1] != T_end: - spike_train = np.append(spike_train, T_end) - return spike_train +from pyspike import SpikeTrain ############################################################ # spike_train_from_string ############################################################ -def spike_train_from_string(s, sep=' ', is_sorted=False): - """ Converts a string of times into an array of spike times. +def spike_train_from_string(s, edges, sep=' ', is_sorted=False): + """ Converts a string of times into a :class:`.SpikeTrain`. - :param s: the string with (ordered) spike times + :param s: the string with (ordered) spike times. + :param edges: interval defining the edges of the spike train. + Given as a pair of floats (T0, T1) or a single float T1, + where T0=0 is assumed. :param sep: The separator between the time numbers, default=' '. :param is_sorted: if True, the spike times are not sorted after loading, if False, spike times are sorted with `np.sort` - :returns: array of spike times + :returns: :class:`.SpikeTrain` """ - if not(is_sorted): - return np.sort(np.fromstring(s, sep=sep)) - else: - return np.fromstring(s, sep=sep) + return SpikeTrain(np.fromstring(s, sep=sep), edges, is_sorted) ############################################################ # load_spike_trains_txt ############################################################ -def load_spike_trains_from_txt(file_name, time_interval=None, +def load_spike_trains_from_txt(file_name, edges, separator=' ', comment='#', is_sorted=False): """ Loads a number of spike trains from a text file. Each line of the text file should contain one spike train as a sequence of spike times separated by `separator`. Empty lines as well as lines starting with `comment` are - neglected. The `time_interval` represents the start and the end of the - spike trains and it is used to add auxiliary spikes at the beginning and - end of each spike train. However, if `time_interval == None`, no auxiliary - spikes are added, but note that the Spike and ISI distance both require - auxiliary spikes. + neglected. The `edges` represents the start and the end of the + spike trains. :param file_name: The name of the text file. - :param time_interval: A pair (T_start, T_end) of values representing the - start and end time of the spike train measurement - or a single value representing the end time, the - T_start is then assuemd as 0. Auxiliary spikes will - be added to the spike train at the beginning and end - of this interval. + :param edges: A pair (T_start, T_end) of values representing the + start and end time of the spike train measurement + or a single value representing the end time, the + T_start is then assuemd as 0. :param separator: The character used to seprate the values in the text file :param comment: Lines starting with this character are ignored. :param sort: If true, the spike times are order via `np.sort`, default=True - :returns: list of spike trains + :returns: list of :class:`.SpikeTrain` """ spike_trains = [] spike_file = open(file_name, 'r') for line in spike_file: if len(line) > 1 and not line.startswith(comment): # use only the lines with actual data and not commented - spike_train = spike_train_from_string(line, separator, is_sorted) - if time_interval is not None: # add auxil. spikes if times given - spike_train = add_auxiliary_spikes(spike_train, time_interval) + spike_train = spike_train_from_string(line, edges, + separator, is_sorted) spike_trains.append(spike_train) return spike_trains @@ -107,18 +62,18 @@ def load_spike_trains_from_txt(file_name, time_interval=None, def merge_spike_trains(spike_trains): """ Merges a number of spike trains into a single spike train. - :param spike_trains: list of arrays of spike times + :param spike_trains: list of :class:`.SpikeTrain` :returns: spike train with the merged spike times """ # get the lengths of the spike trains - lens = np.array([len(st) for st in spike_trains]) + lens = np.array([len(st.spikes) for st in spike_trains]) merged_spikes = np.empty(np.sum(lens)) index = 0 # the index for merged_spikes indices = np.zeros_like(lens) # indices of the spike trains index_list = np.arange(len(indices)) # indices of indices of spike trains # that have not yet reached the end # list of the possible events in the spike trains - vals = [spike_trains[i][indices[i]] for i in index_list] + vals = [spike_trains[i].spikes[indices[i]] for i in index_list] while len(index_list) > 0: i = np.argmin(vals) # the next spike is the minimum merged_spikes[index] = vals[i] # put it to the merged spike train @@ -127,33 +82,34 @@ def merge_spike_trains(spike_trains): indices[i] += 1 # next index for the chosen spike train if indices[i] >= lens[i]: # remove spike train index if ended index_list = index_list[index_list != i] - vals = [spike_trains[n][indices[n]] for n in index_list] - return merged_spikes + vals = [spike_trains[n].spikes[indices[n]] for n in index_list] + return SpikeTrain(merged_spikes, [spike_trains[0].t_start, + spike_trains[0].t_end]) ############################################################ # generate_poisson_spikes ############################################################ -def generate_poisson_spikes(rate, time_interval, add_aux_spikes=True): +def generate_poisson_spikes(rate, interval): """ Generates a Poisson spike train with the given rate in the given time interval :param rate: The rate of the spike trains - :param time_interval: A pair (T_start, T_end) of values representing the - start and end time of the spike train measurement or - a single value representing the end time, the T_start - is then assuemd as 0. Auxiliary spikes will be added - to the spike train at the beginning and end of this - interval, if they are not yet present. - :type time_interval: pair of doubles or double - :returns: Poisson spike train + :param interval: A pair (T_start, T_end) of values representing the + start and end time of the spike train measurement or + a single value representing the end time, the T_start + is then assuemd as 0. Auxiliary spikes will be added + to the spike train at the beginning and end of this + interval, if they are not yet present. + :type interval: pair of doubles or double + :returns: Poisson spike train as a :class:`.SpikeTrain` """ try: - T_start = time_interval[0] - T_end = time_interval[1] + T_start = interval[0] + T_end = interval[1] except: T_start = 0 - T_end = time_interval + T_end = interval # roughly how many spikes are required to fill the interval N = max(1, int(1.2 * rate * (T_end-T_start))) N_append = max(1, int(0.1 * rate * (T_end-T_start))) @@ -165,7 +121,4 @@ def generate_poisson_spikes(rate, time_interval, add_aux_spikes=True): np.random.exponential(1.0/rate, N_append)) spikes = T_start + np.cumsum(intervals) spikes = spikes[spikes < T_end] - if add_aux_spikes: - return add_auxiliary_spikes(spikes, time_interval) - else: - return spikes + return SpikeTrain(spikes, interval) |