facet_form function

A helper function for building a ggplot facet. Used internally by the plotting functions.

facet_form(horiz = NULL, horiz2 = NULL, vert = NULL, vert2 = NULL)

Arguments

• horiz, horiz2: A character string denoting which column to use as the first (horiz) and second (horiz2) level of faceting in the horizontal direction. E.g. "M" or "species". A value of NULL (default) indicates no faceting.
• vert, vert2: A character string denoting which column to use as the first (vert) and second (vert2) level of faceting in the vertical direction. E.g. "M" or "species". A value of NULL (default) indicates no faceting.

Returns

A formula which can be used in facet_grid, or NULL if all arguments are NULL

Author(s)

Cole Monnahan