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reference:ft_mvaranalysis [2018/08/23 14:43] (current)
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 +=====  FT_MVARANALYSIS =====
 +
 +Note that this reference documentation is identical to the help that is displayed in MATLAB when you type "help ft_mvaranalysis"​.
 +
 +<​html><​pre>​
 +  <a href=/​reference/​ft_mvaranalysis><​font color=green>​FT_MVARANALYSIS</​font></​a>​ performs multivariate autoregressive modeling on
 +  time series data over multiple trials.
 + 
 +  Use as
 +    [mvardata] = ft_mvaranalysis(cfg,​ data)
 + 
 +  The input data should be organised in a structure as obtained from
 +  the <a href=/​reference/​ft_preprocessing><​font color=green>​FT_PREPROCESSING</​font></​a>​ function. The configuration depends on the type
 +  of computation that you want to perform.
 +  The output is a data structure of datatype '​mvar'​ which contains the
 +  multivariate autoregressive coefficients in the field coeffs, and the
 +  covariance of the residuals in the field noisecov.
 + 
 +  The configuration should contain:
 +    cfg.method ​    = the name of the toolbox containing the function for the
 +                      actual computation of the ar-coefficients
 +                      this can be '​biosig'​ (default) or '​bsmart'​
 +                      you should have a copy of the specified toolbox in order
 +                      to use mvaranalysis (both can be downloaded directly).
 +    cfg.mvarmethod = scalar (only required when cfg.method = '​biosig'​).
 +                      default is 2, relates to the algorithm used for the
 +                      computation of the AR-coefficients by mvar.m
 +    cfg.order ​     = scalar, order of the autoregressive model (default=10)
 +    cfg.channel ​   = '​all'​ (default) or list of channels for which an mvar model
 +                      is fitted. (Do NOT specify if cfg.channelcmb is
 +                      defined)
 +    cfg.channelcmb = specify channel combinations as a
 +                      two-column cell array with channels in each column between
 +                      which a bivariate model will be fit (overrides
 +                      cfg.channel)
 +    cfg.keeptrials = '​no'​ (default) or '​yes'​ specifies whether the coefficients
 +                      are estimated for each trial seperately, or on the
 +                      concatenated data
 +    cfg.jackknife ​ = '​no'​ (default) or '​yes'​ specifies whether the coefficients
 +                      are estimated for all leave-one-out sets of trials
 +    cfg.zscore ​    = '​no'​ (default) or '​yes'​ specifies whether the channel data
 +                       are z-transformed prior to the model fit. This may be
 +                       ​necessary if the magnitude of the signals is very different
 +                       e.g. when fitting a model to combined MEG/EMG data
 +    cfg.demean ​    = '​yes'​ (default) or '​no'​ explicit removal of DC-offset
 +    cfg.ems ​       = '​no'​ (default) or '​yes'​ explicit removal ensemble mean
 + 
 +  ft_mvaranalysis can be used to obtain one set of coefficients across
 +  all time points in the data, also when the trials are of varying length.
 + 
 +  ft_mvaranalysis can be also used to obtain time-dependent sets of
 +  coefficients based on a sliding window. In this case the input cfg
 +  should contain:
 + 
 +    cfg.t_ftimwin = the width of the sliding window on which the coefficients
 +                     are estimated
 +    cfg.toi ​      = [t1 t2 ... tx] the time points at which the windows are
 +                     ​centered
 + 
 +  To facilitate data-handling and distributed computing you can use
 +    cfg.inputfile ​  ​= ​ ...
 +    cfg.outputfile ​ =  ...
 +  If you specify one of these (or both) the input data will be read from a *.mat
 +  file on disk and/or the output data will be written to a *.mat file. These mat
 +  files should contain only a single variable, corresponding with the
 +  input/​output structure.
 + 
 +  See also <a href=/​reference/​ft_preprocessing><​font color=green>​FT_PREPROCESSING</​font></​a>,​ <a href=/​reference/​ft_sourcestatistics><​font color=green>​FT_SOURCESTATISTICS</​font></​a>,​ <a href=/​reference/​ft_freqstatistics><​font color=green>​FT_FREQSTATISTICS</​font></​a>,​
 +  <a href=/​reference/​ft_timelockstatistics><​font color=green>​FT_TIMELOCKSTATISTICS</​font></​a>​
 +</​pre></​html>​