stat_scalpmap creates an interpolated surface for an irregular set of x-y coordinates, as is typically required for a topographical EEG plot. Since the surface should be approximately round, the function attempts to blank out portions of the surface that lay outside the area within the electrodes.

geom_head() adds a headshape to a plot.

geom_mask() adds a masking ring to smooth the edges of a scalp map generated by stat_scalpmap(), to give it a circular appearance.

geom_ears simply draws a pair of ears attached to the head shape.

geom_channels adds either points or text labels at channel locations. This is a convenience function to prevent overplotting when the input data contains many rows of data.

stat_scalpmap(mapping = NULL, data = NULL, position = "identity",
  na.rm = FALSE, show.legend = NA, inherit.aes = TRUE,
  grid_res = 300, interpolate = FALSE, interp_limit = "skirt", ...)

geom_head(mapping = NULL, data = NULL, show.legend = NA,
  na.rm = TRUE, inherit.aes = TRUE, interp_limit = "skirt",
  r = NULL, ...)

geom_mask(mapping = NULL, data = NULL, show.legend = NA,
  na.rm = FALSE, colour = "white", size = rel(6.5),
  scale_fac = 1.32, ...)

geom_ears(mapping = NULL, data = NULL, show.legend = NA,
  na.rm = FALSE, ...)

geom_channels(mapping = NULL, data = NULL, geom = "point",
  show.legend = NA, inherit.aes = TRUE, na.rm = TRUE, ...)



Set of aesthetic mappings created by aes() or aes_(). If specified and inherit.aes = TRUE (the default), it is combined with the default mapping at the top level of the plot. You must supply mapping if there is no plot mapping.


The data to be displayed in this layer. There are three options:

If NULL, the default, the data is inherited from the plot data as specified in the call to ggplot().

A data.frame, or other object, will override the plot data. All objects will be fortified to produce a data frame. See fortify() for which variables will be created.

A function will be called with a single argument, the plot data. The return value must be a data.frame, and will be used as the layer data.


Position adjustment, either as a string, or the result of a call to a position adjustment function.


If FALSE, the default, missing values are removed with a warning. If TRUE, missing values are silently removed.


logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes. It can also be a named logical vector to finely select the aesthetics to display.


If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders().


Resolution of the interpolation grid. (Defaults to 100 points).


If TRUE interpolate linearly, if FALSE (the default) don't interpolate.


Topoplot with a "skirt" or inside the "head".


Other arguments passed on to layer(). These are often aesthetics, used to set an aesthetic to a fixed value, like colour = "red" or size = 3. They may also be parameters to the paired geom/stat.


Radius of head


For geom_mask, colour of the masking ring.


For geom_mask, width of the masking ring.


The radius of the ring is determined from the front-most electrode's location by a scaling factor. Defaults to 1.32 * max(y).


"point" for points or "text" for labels. Default is "point".

See also

Other topoplot functions: geom_topo

Other topoplot functions: geom_topo

Other topoplot functions: geom_topo