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reference:ft_artifact_zvalue [2018/08/23 14:43] (current)
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 +=====  FT_ARTIFACT_ZVALUE =====
 +
 +Note that this reference documentation is identical to the help that is displayed in MATLAB when you type "help ft_artifact_zvalue"​.
 +
 +<​html><​pre>​
 +  <a href=/​reference/​ft_artifact_zvalue><​font color=green>​FT_ARTIFACT_ZVALUE</​font></​a>​ reads the interesting segments of data from file and identifies
 +  artifacts by means of thresholding the z-transformed value of the preprocessed raw data.
 +  Depending on the preprocessing options, this method will be sensitive to EOG, muscle or
 +  jump artifacts. ​ This procedure only works on continuously recorded data.
 + 
 +  Use as
 +    [cfg, artifact] = ft_artifact_zvalue(cfg)
 +  with the configuration options
 +    cfg.dataset ​    = string with the filename
 +  or
 +    cfg.headerfile ​ = string with the filename
 +    cfg.datafile ​   = string with the filename
 +  and optionally
 +    cfg.headerformat
 +    cfg.dataformat
 + 
 +  Alternatively you can use it as
 +    [cfg, artifact] = ft_artifact_zvalue(cfg,​ data)
 +  where the input data is a structure as obtained from <a href=/​reference/​ft_preprocessing><​font color=green>​FT_PREPROCESSING</​font></​a>​.
 + 
 +  The required configuration settings are:
 +    cfg.trl ​        = structure that defines the data segments of interest. See <a href=/​reference/​ft_definetrial><​font color=green>​FT_DEFINETRIAL</​font></​a>​
 +    cfg.continuous ​ = '​yes'​ or '​no'​ whether the file contains continuous data (default ​  = '​yes'​)
 +  and
 +    cfg.artfctdef.zvalue.channel
 +    cfg.artfctdef.zvalue.cutoff
 +    cfg.artfctdef.zvalue.trlpadding
 +    cfg.artfctdef.zvalue.fltpadding
 +    cfg.artfctdef.zvalue.artpadding
 + 
 +  If you encounter difficulties with memory usage, you can use
 +    cfg.memory = '​low'​ or '​high',​ whether to be memory or computationally efficient, respectively (default = '​high'​)
 + 
 +  The optional configuration settings (see below) are:
 +    cfg.artfctdef.zvalue.artfctpeak ​ = '​yes'​ or '​no'​
 +    cfg.artfctdef.zvalue.interactive = '​yes'​ or '​no'​
 + 
 +  If you specify artfctpeak='​yes',​ the maximum value of the artifact within its range
 +  will be found and saved into cfg.artfctdef.zvalue.peaks.
 + 
 +  If you specify interactive='​yes',​ a GUI will be started and you can manually
 +  accept/​reject detected artifacts, and/or change the threshold. To control the
 +  graphical interface via keyboard, use the following keys:
 + 
 +      q                 : Stop
 + 
 +      comma             : Step to the previous artifact trial
 +      a                 : Specify artifact trial to display
 +      period ​           : Step to the next artifact trial
 + 
 +      x                 : Step 10 trials back
 +      leftarrow ​        : Step to the previous trial
 +      t                 : Specify trial to display
 +      rightarrow ​       : Step to the next trial
 +      c                 : Step 10 trials forward
 + 
 +      k                 : Keep trial
 +      space             : Mark complete trial as artifact
 +      r                 : Mark part of trial as artifact
 + 
 +      downarrow ​        : Shift the z-threshold down
 +      z                 : Specify the z-threshold
 +      uparrow ​          : Shift the z-threshold down
 + 
 +  Use also, e.g. as input to DSS option of ft_componentanalysis
 +  cfg.artfctdef.zvalue.artfctpeakrange=[-0.25 0.25], for example to indicate range
 +  around peak to include, saved into cfg.artfctdef.zvalue.dssartifact. The default is
 +  [0 0]. Range will respect trial boundaries (i.e. be shorter if peak is near
 +  beginning or end of trial). Samples between trials will be removed; thus this won't
 +  match .sampleinfo of the data structure.
 + 
 +  Configuration settings related to the preprocessing of the data are
 +    cfg.artfctdef.zvalue.lpfilter ​     = '​no'​ or '​yes' ​ lowpass filter
 +    cfg.artfctdef.zvalue.hpfilter ​     = '​no'​ or '​yes' ​ highpass filter
 +    cfg.artfctdef.zvalue.bpfilter ​     = '​no'​ or '​yes' ​ bandpass filter
 +    cfg.artfctdef.zvalue.bsfilter ​     = '​no'​ or '​yes' ​ bandstop filter for line noise removal
 +    cfg.artfctdef.zvalue.dftfilter ​    = '​no'​ or '​yes' ​ line noise removal using discrete fourier transform
 +    cfg.artfctdef.zvalue.medianfilter ​ = '​no'​ or '​yes' ​ jump preserving median filter
 +    cfg.artfctdef.zvalue.lpfreq ​       = lowpass ​ frequency in Hz
 +    cfg.artfctdef.zvalue.hpfreq ​       = highpass frequency in Hz
 +    cfg.artfctdef.zvalue.bpfreq ​       = bandpass frequency range, specified as [low high] in Hz
 +    cfg.artfctdef.zvalue.bsfreq ​       = bandstop frequency range, specified as [low high] in Hz
 +    cfg.artfctdef.zvalue.lpfiltord ​    = lowpass ​ filter order
 +    cfg.artfctdef.zvalue.hpfiltord ​    = highpass filter order
 +    cfg.artfctdef.zvalue.bpfiltord ​    = bandpass filter order
 +    cfg.artfctdef.zvalue.bsfiltord ​    = bandstop filter order
 +    cfg.artfctdef.zvalue.medianfiltord = length of median filter
 +    cfg.artfctdef.zvalue.lpfilttype ​   = digital filter type, '​but'​ (default) or '​firws'​ or '​fir'​ or '​firls'​
 +    cfg.artfctdef.zvalue.hpfilttype ​   = digital filter type, '​but'​ (default) or '​firws'​ or '​fir'​ or '​firls'​
 +    cfg.artfctdef.zvalue.bpfilttype ​   = digital filter type, '​but'​ (default) or '​firws'​ or '​fir'​ or '​firls'​
 +    cfg.artfctdef.zvalue.bsfilttype ​   = digital filter type, '​but'​ (default) or '​firws'​ or '​fir'​ or '​firls'​
 +    cfg.artfctdef.zvalue.detrend ​      = '​no'​ or '​yes'​
 +    cfg.artfctdef.zvalue.demean ​       = '​no'​ or '​yes'​
 +    cfg.artfctdef.zvalue.baselinewindow = [begin end] in seconds, the default is the complete trial
 +    cfg.artfctdef.zvalue.hilbert ​      = '​no'​ or '​yes'​
 +    cfg.artfctdef.zvalue.rectify ​      = '​no'​ or '​yes'​
 + 
 +  The output argument "​artifact"​ is a Nx2 matrix comparable to the
 +  "​trl"​ matrix of <a href=/​reference/​ft_definetrial><​font color=green>​FT_DEFINETRIAL</​font></​a>​. The first column of which specifying the
 +  beginsamples of an artifact period, the second column contains the
 +  endsamples of the artifactperiods.
 + 
 +  See also <a href=/​reference/​ft_rejectartifact><​font color=green>​FT_REJECTARTIFACT</​font></​a>,​ <a href=/​reference/​ft_artifact_clip><​font color=green>​FT_ARTIFACT_CLIP</​font></​a>,​ <a href=/​reference/​ft_artifact_ecg><​font color=green>​FT_ARTIFACT_ECG</​font></​a>,​ <a href=/​reference/​ft_artifact_eog><​font color=green>​FT_ARTIFACT_EOG</​font></​a>,​
 +  <a href=/​reference/​ft_artifact_jump><​font color=green>​FT_ARTIFACT_JUMP</​font></​a>,​ <a href=/​reference/​ft_artifact_muscle><​font color=green>​FT_ARTIFACT_MUSCLE</​font></​a>,​ <a href=/​reference/​ft_artifact_threshold><​font color=green>​FT_ARTIFACT_THRESHOLD</​font></​a>,​ <a href=/​reference/​ft_artifact_zvalue><​font color=green>​FT_ARTIFACT_ZVALUE</​font></​a>​
 +</​pre></​html>​