Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_spike_rate”.

  FT_SPIKE_RATE computes the firing rate of spiketrains and their variance
  Use as
    [rate] = ft_spike_rate(cfg, spike)
  The input SPIKE should be organised as the spike or the (binary) raw
  datatype, obtained from FT_SPIKE_MAKETRIALS or FT_APPENDSPIKE (in that
  case, conversion is done within the function)
    cfg.outputunit       = 'rate' (default) or 'spikecount'. If 'rate', we convert
                           the output per trial to firing rates (spikes/sec).
                           If 'spikecount', we count the number spikes per trial.
    cfg.spikechannel     = see FT_CHANNELSELECTION for details
    cfg.trials           = vector of indices (e.g., 1:2:10)
                           logical selection of trials (e.g., [1010101010])
                           'all' (default), selects all trials%   cfg.trials
    cfg.vartriallen      = 'yes' (default) or 'no'.
                           If 'yes' - accept variable trial lengths and use all available trials
                           and the samples in every trial.
                           If 'no'  - only select those trials that fully cover the window as
                           specified by cfg.latency and discard those trials that do not.
    cfg.latency          = [begin end] in seconds
                           'maxperiod' (default)
                           'minperiod', i.e., the minimal period all trials share
                           'prestim' (all t<=0)
                           'poststim' (all t>=0).
    cfg.keeptrials       = 'yes' or 'no' (default).
  The outputs from spike is a TIMELOCK structure (see FT_DATATYPE_TIMELOCK)
    rate.trial:        nTrials x nUnits matrix containing the firing rate per unit and trial
    rate.avg:          nTrials array containing the average firing rate per unit
    rate.var:          nTrials array containing the variance of firing rates per unit
    rate.dof:          nTrials array containing the degree of freedom per unit
    rate.label:        nUnits cell array containing the labels of the neuronal units%
    rate.time:         Mean latency (this field ensures it is TIMELOCK