Add synchrony metrics to quality metrics

doc/modules/qualitymetrics/synchrony_metrics.rst

@@ -0,0 +1,49 @@
+Synchrony Metrics (:code:`synchrony_metrics`)
+=======================================
+
+Calculation
+-----------
+This function is providing a metric for the presence of synchronous spiking events across multiple spike trains.
+
+The complexity is used to characterize synchronous events within the same spike train and across different spike
+trains. This way synchronous events can be found both in multi-unit and single-unit spike trains.
+
+Complexity is calculated by counting the number of spikes (i.e. non-empty bins) that occur separated by spread - 1 or less empty bins,
+within and across spike trains in the spiketrains list.
+
+Expectation and use
+-------------------
+A larger value indicates a higher synchrony of the respective spike train with the other spike trains.
+
+Example code
+------------
+
+.. code-block:: python
+
+    import spikeinterface.qualitymetrics as qm
+    # Make recording, sorting and wvf_extractor object for your data.
+    presence_ratio = qm.compute_synchrony_metrics(wvf_extractor)
+    # presence_ratio is a tuple of dicts with the synchrony metrics for each unit
+
+Links to source code
+--------------------
+
+From `Elephant - Electrophysiology Analysis Toolkit <https://github.com/NeuralEnsemble/elephant/blob/master/elephant/spike_train_synchrony.py#L245>`_
+
+
+References
+----------
+
+.. automodule:: spikeinterface.toolkit.qualitymetrics.misc_metrics
+
+    .. autofunction:: compute_synchrony_metrics
+
+Literature
+----------
+
+Described in Gruen_
+
+Citations
+---------
+.. [Gruen] Sonja Grün, Moshe Abeles, and Markus Diesmann. Impact of higher-order correlations on coincidence distributions of massively parallel data.
+In International School on Neural Networks, Initiated by IIASS and EMFCSC, volume 5286, 96–114. Springer, 2007.

pyproject.toml

@@ -125,7 +125,7 @@ test = [
     # for release we need pypi, so this need to be commented
     "probeinterface @ git+https://github.com/SpikeInterface/probeinterface.git",
     "neo @ git+https://github.com/NeuralEnsemble/python-neo.git",
-    
+
 ]