redefinetrial#

syncopy.redefinetrial(data_obj, trials=None, minlength=None, offset=None, toilim=None, begsample=None, endsample=None, trl=None)[source]#

This function allows you to adjust the time axis of your data, i.e. to change from stimulus-locked to response-locked. Furthermore, it allows you to select a time window of interest, or to resegment your long trials into shorter fragments.

The parameters listed below can be provided as is or a via a cfg configuration ‘structure’, see Notes for details.

Parameters:

  • data_obj (Syncopy data object (BaseData-like)) –

  • trials (list or ndarray) – List of integers representing trial numbers to be selected

  • minlength (float or str) – Minimum length of trials in seconds, can be ‘maxperlen’. Trials which are shorter get thrown out.

  • toilim ([begin, end]) – specify latency window in seconds, to cut out a time window of interest from each trial.

  • offset (int or Mx1 ndarray) – Realign the time axes of all trials to a new reference time point (i.e. change the definition of t=0). Expressed in samples relative to current t=0.

  • begsample (int or Mx1 ndarray of ints) – Specify the begin sample for each trial (see also endsample). Expressed in samples relative to the start of the input trial.

  • endsample (int or Mx1 ndarray of ints) – Specify the end sample for each trial (see also begsample). Expressed in samples relative to the start of the input trial.

  • trl (Mx3 ndarray) – New trial definition. [start, stop, trigger_offset] sample indices for M trials

Returns:

ret_obj

Return type:

Syncopy data object (BaseData-like))

Notes

This function can be either called providing its input arguments directly or via a cfg configuration ‘structure’. For instance, the following function calls are equivalent

>>> spy.redefinetrial(data_obj, trials=...)
>>> cfg = spy.StructDict()
>>> cfg.trials = ...
>>> spy.redefinetrial(cfg, data_obj)
>>> cfg.data_obj = data_obj
>>> spy.redefinetrial(cfg)

Please refer to Syncopy for FieldTrip Users for further details.

This is a compatibility function, mimicking ft_redefinetrial. However, if selected sample ranges (via toilim or trl) are (partially) outside of the available data, an error is thrown. This is different to FieldTrips’ implementation, where missing data is filled up with NaNs.

See also

definetrialdefinetrial()

Manipulate the trial definition

selectdataselectdata()

Select along general attributes like channel, frequency, etc.

FieldTrip’s redefinetrial <https://https://github.com/fieldtrip/fieldtrip/blob/master/ft_redefinetrial.m>