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

  FT_DATABROWSER can be used for visual inspection of data. Artifacts that were
  detected by artifact functions (see FT_ARTIFACT_xxx functions where xxx is the type
  of artifact) are marked. Additionally data pieces can be marked and unmarked as
  artifact by manual selection. The output cfg contains the updated specification of
  the artifacts.
  Use as
    cfg = ft_databrowser(cfg)
    cfg = ft_databrowser(cfg, data)
  If you only specify the configuration structure, it should contain the name of the
  dataset on your hard disk (see below). If you specify input data, it should be a
  data structure as obtained from FT_PREPROCESSING or from FT_COMPONENTANALYSIS.
  If you want to browse data that is on disk, you have to specify
    cfg.dataset                 = string with the filename
  Instead of specifying the dataset, you can also explicitely specify the name of the
  file containing the header information and the name of the file containing the
  data, using
    cfg.datafile                = string with the filename
    cfg.headerfile              = string with the filename
  The following configuration options are supported:
    cfg.ylim                    = vertical scaling, can be 'maxmin', 'maxabs' or [ymin ymax] (default = 'maxabs')
    cfg.zlim                    = color scaling to apply to component topographies, 'minmax', 'maxabs' (default = 'maxmin')
    cfg.blocksize               = duration in seconds for cutting the data up
    cfg.trl                     = structure that defines the data segments of interest, only applicable for trial-based data
    cfg.continuous              = 'yes' or 'no' whether the data should be interpreted as continuous or trial-based                 = cell-array with channel labels, see FT_CHANNELSELECTION
    cfg.plotlabels              = 'yes' (default), 'no', 'some'; whether to plot channel labels in vertical
                                  viewmode ('some' plots one in every ten labels; useful when plotting a
                                  large number of channels at a time)
    cfg.ploteventlabels         = 'type=value', 'colorvalue' (default = 'type=value');
    cfg.viewmode                = string, 'butterfly', 'vertical', 'component' for visualizing components e.g. from an ICA (default is 'butterfly')  = Nx2 matrix with artifact segments see FT_ARTIFACT_xxx functions
    cfg.selectfeature           = string, name of feature to be selected/added (default = 'visual')
    cfg.selectmode              = 'markartifact', 'markpeakevent', 'marktroughevent' (default = 'markartifact')
    cfg.colorgroups             = 'sequential' 'allblack' 'labelcharx' (x = xth character in label), 'chantype' or
                                   vector with length(data/hdr.label) defining groups (default = 'sequential')
    cfg.channelcolormap         = COLORMAP (default = customized lines map with 15 colors)
    cfg.verticalpadding         = number or 'auto', padding to be added to top and bottom of plot to avoid channels largely dissappearing when viewmode = 'vertical'/'component'  (default = 'auto')
                                  padding is expressed as a proportion of the total height added to the top, and bottom) ('auto' adds padding depending on the number of channels being plotted)
    cfg.selfun                  = string, name of function which is evaluated using the right-click context menu
                                   The selected data and cfg.selcfg are passed on to this function.
    cfg.selcfg                  = configuration options for function in cfg.selfun
    cfg.seldat                  = 'selected' or 'all', specifies whether only the currently selected or all channels
                                  will be passed to the selfun (default = 'selected')
    cfg.renderer                = string, 'opengl', 'zbuffer', 'painters', see MATLAB Figure Properties.
                                  If the databrowser crashes, set to 'painters'.
  The following options for the scaling of the EEG, EOG, ECG, EMG and MEG channels is
  optional and can be used to bring the absolute numbers of the different channel
  types in the same range (e.g. fT and uV). The channel types are determined from the
  input data using FT_CHANNELSELECTION.
    cfg.eegscale                = number, scaling to apply to the EEG channels prior to display
    cfg.eogscale                = number, scaling to apply to the EOG channels prior to display
    cfg.ecgscale                = number, scaling to apply to the ECG channels prior to display
    cfg.emgscale                = number, scaling to apply to the EMG channels prior to display
    cfg.megscale                = number, scaling to apply to the MEG channels prior to display
    cfg.gradscale               = number, scaling to apply to the MEG gradiometer channels prior to display (in addition to the cfg.megscale factor)
    cfg.magscale                = number, scaling to apply to the MEG magnetometer channels prior to display (in addition to the cfg.megscale factor)
    cfg.mychanscale             = number, scaling to apply to the channels specified in cfg.mychan
    cfg.mychan                  = Nx1 cell-array with selection of channels
    cfg.chanscale               = Nx1 vector with scaling factors, one per channel specified in
    cfg.compscale               = string, 'global' or 'local', defines whether the colormap for the topographic scaling is
                                  applied per topography or on all visualized components (default 'global')
  You can specify preprocessing options that are to be applied to the  data prior to
  display. Most options from FT_PREPROCESSING are supported. They should be specified
  in the sub-structure cfg.preproc like these examples
    cfg.preproc.lpfilter        = 'no' or 'yes'  lowpass filter (default = 'no')
    cfg.preproc.lpfreq          = lowpass  frequency in Hz
    cfg.preproc.demean          = 'no' or 'yes', whether to apply baseline correction (default = 'no')
    cfg.preproc.detrend         = 'no' or 'yes', remove linear trend from the data (done per trial) (default = 'no')
    cfg.preproc.baselinewindow  = [begin end] in seconds, the default is the complete trial (default = 'all')
  In case of component viewmode, a layout is required. If no layout is specified, an
  attempt is made to construct one from the sensor definition that is present in the
  data or specified in the configuration.
    cfg.layout                  = filename of the layout, see FT_PREPARE_LAYOUT
    cfg.elec                    = structure with electrode positions, see FT_DATATYPE_SENS
    cfg.grad                    = structure with gradiometer definition, see FT_DATATYPE_SENS
    cfg.elecfile                = name of file containing the electrode positions, see FT_READ_SENS
    cfg.gradfile                = name of file containing the gradiometer definition, see FT_READ_SENS
  The default font size might be too small or too large, depending on the number of
  channels. You can use the following options to change the size of text inside the
  figure and along the axes.
    cfg.fontsize                = number, fontsize inside the figure (default = 0.03)
    cfg.fontunits               = string, can be 'normalized', 'points', 'pixels', 'inches' or 'centimeters' (default = 'normalized')
    cfg.axisfontsize            = number, fontsize along the axes (default = 10)
    cfg.axisfontunits           = string, can be 'normalized', 'points', 'pixels', 'inches' or 'centimeters' (default = 'points')
    cfg.linewidth               = number, width of plotted lines (default = 0.5)
  When visually selection data, a right-click will bring up a context-menu containing
  functions to be executed on the selected data. You can use your own function using
  cfg.selfun and cfg.selcfg. You can use multiple functions by giving the names/cfgs
  as a cell-array.
  In butterfly and vertical mode, you can use the "identify" button to reveal the name of a
  channel. Please be aware that it searches only vertically. This means that it will
  return the channel with the amplitude closest to the point you have clicked at the
  specific time point. This might be counterintuitive at first.
  The "cfg.artifact" field in the output cfg is a Nx2 matrix comparable to the
  "cfg.trl" matrix of FT_DEFINETRIAL. The first column of which specifying the
  beginsamples of an artifact period, the second column contains the endsamples of
  the artifactperiods.
  Note for debugging: in case the databrowser crashes, use delete(gcf) to kill the