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

  FT_TOPOPLOTER plots the topographic distribution over the head
  of a 2-dimensional data representations such as the event-related
  fields or potentials or the power- or coherence spectrum.
 
  Use as
    ft_topoplotER(cfg, timelock)
  or
    ft_topoplotER(cfg, freq)
 
  The data can be an erp/erf produced by FT_TIMELOCKANALYSIS, a powerspectrum
  (without time dimension) produced by FT_FREQANALYSIS or a connectivityspectrum
  produced by FT_CONNECTIVITYANALYSIS.  Also, the output to FT_FREQSTATISTICS
  and FT_TIMELOCKSTATISTICS can be visualised.
 
  The configuration can have the following parameters
    cfg.parameter          = field that contains the data to be plotted as color, for example 'avg', 'powspctrm' or 'cohspctrm' (default is automatic)
    cfg.maskparameter      = field in the data to be used for masking of data. It should have alues between 0 and 1, where 0 corresponds to transparent.
    cfg.xlim               = limit for 1st dimension in data (e.g., time), can be 'maxmin' or [xmin xmax] (default = 'maxmin')
    cfg.zlim               = limits for color dimension, 'maxmin', 'maxabs', 'zeromax', 'minzero', or [zmin zmax] (default = 'maxmin')
    cfg.channel            = Nx1 cell-array with selection of channels (default = 'all'), see FT_CHANNELSELECTION for details
    cfg.refchannel         = name of reference channel for visualising connectivity, can be 'gui'
    cfg.baseline           = 'yes','no' or [time1 time2] (default = 'no'), see FT_TIMELOCKBASELINE or FT_FREQBASELINE
    cfg.baselinetype       = 'absolute' or 'relative' (default = 'absolute')
    cfg.trials             = 'all' or a selection given as a 1xN vector (default = 'all')
    cfg.colormap           = any sized colormap, see COLORMAP
    cfg.marker             = 'on', 'labels', 'numbers', 'off'
    cfg.markersymbol       = channel marker symbol (default = 'o')
    cfg.markercolor        = channel marker color (default = [0 0 0] (black))
    cfg.markersize         = channel marker size (default = 2)
    cfg.markerfontsize     = font size of channel labels (default = 8 pt)
    cfg.highlight          = 'off', 'on', 'labels', 'numbers'
    cfg.highlightchannel   =  Nx1 cell-array with selection of channels, or vector containing channel indices see FT_CHANNELSELECTION
    cfg.highlightsymbol    = highlight marker symbol (default = 'o')
    cfg.highlightcolor     = highlight marker color (default = [0 0 0] (black))
    cfg.highlightsize      = highlight marker size (default = 6)
    cfg.highlightfontsize  = highlight marker size (default = 8)
    cfg.hotkeys            = enables hotkeys (pageup/pagedown/m) for dynamic zoom and translation (ctrl+) of the color limits
    cfg.colorbar           = 'yes'
                             'no' (default)
                             'North'              inside plot box near top
                             'South'              inside bottom
                             'East'               inside right
                             'West'               inside left
                             'NorthOutside'       outside plot box near top
                             'SouthOutside'       outside bottom
                             'EastOutside'        outside right
                             'WestOutside'        outside left
    cfg.interplimits       = limits for interpolation (default = 'head')
                             'electrodes' to furthest electrode
                             'head' to edge of head
    cfg.interpolation      = 'linear','cubic','nearest','v4' (default = 'v4') see GRIDDATA
    cfg.style              = plot style (default = 'both')
                             'straight' colormap only
                             'contour' contour lines only
                             'both' (default) both colormap and contour lines
                             'fill' constant color between lines
                             'blank' only the head shape
    cfg.gridscale          = scaling grid size (default = 67)
                             determines resolution of figure
    cfg.shading            = 'flat' or 'interp' (default = 'flat')
    cfg.comment            = 'no', 'auto' or 'xlim' (default = 'auto')
                             'auto': date, xparam and zparam limits are printed
                             'xlim': only xparam limits are printed
    cfg.commentpos         = string or two numbers, position of comment (default 'leftbottom')
                             'lefttop' 'leftbottom' 'middletop' 'middlebottom' 'righttop' 'rightbottom'
                             'title' to place comment as title
                             'layout' to place comment as specified for COMNT in layout
                             [x y] coordinates
    cfg.interactive        = Interactive plot 'yes' or 'no' (default = 'yes')
                             In a interactive plot you can select areas and produce a new
                             interactive plot when a selected area is clicked. Multiple areas
                             can be selected by holding down the SHIFT key.
    cfg.directionality     = '', 'inflow' or 'outflow' specifies for
                             connectivity measures whether the inflow into a
                             node, or the outflow from a node is plotted. The
                             (default) behavior of this option depends on the dimor
                             of the input data (see below).
    cfg.layout             = specify the channel layout for plotting using one of
                             the supported ways (see below).
    cfg.interpolatenan     = string 'yes', 'no' (default = 'yes')
                             interpolate over channels containing NaNs
 
  For the plotting of directional connectivity data the cfg.directionality
  option determines what is plotted. The default value and the supported
  functionality depend on the dimord of the input data. If the input data
  is of dimord 'chan_chan_XXX', the value of directionality determines
  whether, given the reference channel(s), the columns (inflow), or rows
  (outflow) are selected for plotting. In this situation the default is
  'inflow'. Note that for undirected measures, inflow and outflow should
  give the same output. If the input data is of dimord 'chancmb_XXX', the
  value of directionality determines whether the rows in data.labelcmb are
  selected. With 'inflow' the rows are selected if the refchannel(s) occur in
  the right column, with 'outflow' the rows are selected if the
  refchannel(s) occur in the left column of the labelcmb-field. Default in
  this case is '', which means that all rows are selected in which the
  refchannel(s) occur. This is to robustly support linearly indexed
  undirected connectivity metrics. In the situation where undirected
  connectivity measures are linearly indexed, specifying 'inflow' or
  'outflow' can result in unexpected behavior.
 
  The layout defines how the channels are arranged. You can specify the
  layout in a variety of ways:
   - you can provide a pre-computed layout structure, see FT_PREPARE_LAYOUT
   - you can give the name of an ascii layout file with extension *.lay
   - you can give the name of an electrode file
   - you can give an electrode definition, i.e. "elec" structure
   - you can give a gradiometer definition, i.e. "grad" structure
  If you do not specify any of these and the data structure contains an
  electrode or gradiometer structure, that will be used for creating a
  layout. If you want to have more fine-grained control over the layout
  of the subplots, you should create your own layout file.
 
  See also FT_SINGLEPLOTER, FT_MULTIPLOTER, FT_SINGLEPLOTTFR, FT_MULTIPLOTTFR,
  FT_TOPOPLOTTFR, FT_PREPARE_LAYOUT