Helper function for building a ggplot facet

Source: R/plot_functions.R

Used internally by the plotting functions to create faceting formulas.

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 in the horizontal space.

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 in the vertical space.

Value

A formula which can be used in ggplot2::facet_grid() or NULL

if all arguments are NULL.

Author

Cole Monnahan