+merge_spike_trains

3 files changed, 26 insertions, 12 deletions

diff --git a/pyspike/__init__.py b/pyspike/__init__.py
index 6651eb5..6895bd8 100644
--- a/pyspike/__init__.py
+++ b/pyspike/__init__.py
@@ -2,4 +2,4 @@ __all__ = ["function", "distances", "spikes"]
 
 from function import PieceWiseConstFunc
 from distances import isi_distance
-from spikes import spike_train_from_string
+from spikes import spike_train_from_string, merge_spike_trains
diff --git a/pyspike/distances.py b/pyspike/distances.py
index d9790dc..7044a52 100644
--- a/pyspike/distances.py
+++ b/pyspike/distances.py
@@ -9,16 +9,6 @@ import numpy as np
 
 from pyspike import PieceWiseConstFunc
 
-def spike_train_from_string(s, sep=' '):
-    """ Converts a string of times into a SpikeTrain object.
-    Params:
-    - s: the string with (ordered) spike times
-    - sep: The separator between the time numbers.
-    Returns:
-    - array of spike times
-    """
-    return np.fromstring(s, sep=sep)
-
 def isi_distance(spikes1, spikes2, T_end, T_start=0.0):
     """ Computes the instantaneous isi-distance S_isi (t) of the two given spike
     trains. 
diff --git a/pyspike/spikes.py b/pyspike/spikes.py
index 42b6501..66ef554 100644
--- a/pyspike/spikes.py
+++ b/pyspike/spikes.py
@@ -8,7 +8,7 @@ Copyright 2014, Mario Mulansky <mario.mulansky@gmx.net>
 import numpy as np
 
 def spike_train_from_string(s, sep=' '):
-    """ Converts a string of times into a SpikeTrain object.
+    """ Converts a string of times into an array of spike times.
     Params:
     - s: the string with (ordered) spike times
     - sep: The separator between the time numbers.
@@ -16,3 +16,27 @@ def spike_train_from_string(s, sep=' '):
     - array of spike times
     """
     return np.fromstring(s, sep=sep)
+
+
+def merge_spike_trains( spike_trains ):
+    """ Merges a number of spike trains into a single spike train.
+    Params:
+    - spike_trains: list of arrays of spike times
+    Returns:
+    - array with the merged spike times
+    """
+    # get the lengths of the spike trains
+    lens = np.array([len(st) for st in spike_trains])
+    merged_spikes = np.empty(np.sum(lens))
+    index = 0
+    indices = np.zeros_like(lens)
+    vals = [spike_trains[i][indices[i]] for i in xrange(len(indices))]
+    while len(indices) > 0:
+        i = np.argmin(vals)
+        merged_spikes[index] = vals[i]
+        index += 1
+        indices[i] += 1
+        if indices[i] >= lens[i]:
+            indices = np.delete(indices, i)
+        vals = [spike_trains[i][indices[i]] for i in xrange(len(indices))]
+    return merged_spikes