This function creates a ggplot object with customized axes range (same for both), names and background
background.plot(range_faxes, faxes_nm, color_bg)
a vector with minimum and maximum values of axes. Note
that to have a fair representation of position of species in all plots,
they should have the same range. Default:
range_faxes = c(NA, NA) (the
range is computed according to the range of values among all axes).
a vector with axes labels for figure.
a R color name or an hexadecimal code used to fill plot
color_bg = "grey95".
A ggplot object plotting background of multidimensional graphs.