Plot a histogram of a continuous variable xvar, faceted on a categorical conditioning variable, condvar. Each faceted plot also shows a "shadow plot" of the unconditioned histogram for comparison.

ShadowHist(
  frm,
  xvar,
  condvar,
  title,
  ...,
  ncol = 1,
  monochrome = FALSE,
  palette = "Dark2",
  fillcolor = "darkblue",
  bins = 30,
  binwidth = NULL
)

Arguments

frm

data frame to get values from.

xvar

name of the primary continuous variable

condvar

name of conditioning variable (categorical variable, controls faceting).

title

title to place on plot.

...

no unnamed argument, added to force named binding of later arguments.

ncol

numeric: number of columns in facet_wrap.

monochrome

logical: if TRUE, all facets filled with same color

palette

character: if monochrome==FALSE, name of brewer color palette (can be NULL)

fillcolor

character: if monochrome==TRUE, name of fill color

bins

number of bins. Defaults to thirty.

binwidth

width of the bins. Overrides bins.

Value

a ggplot2 histogram plot

Details

Currently supports only the bins and binwidth arguments (see geom_histogram), but not the center, boundary, or breaks arguments.

By default, the facet plots are arranged in a single column. This can be changed with the optional ncol argument.

If palette is NULL, and monochrome is FALSE, plot colors will be chosen from the default ggplot2 palette. Setting palette to NULL allows the user to choose a non-Brewer palette, for example with scale_fill_manual. For consistency with previous releases, ShadowHist defaults to monochrome = FALSE, while ShadowPlot defaults to monochrome = TRUE.

Please see here for some interesting discussion https://drsimonj.svbtle.com/plotting-background-data-for-groups-with-ggplot2.

Examples

ShadowHist(iris, "Petal.Length", "Species", title = "Petal Length distribution by Species")
# make all the facets the same color ShadowHist(iris, "Petal.Length", "Species", monochrome=TRUE, title = "Petal Length distribution by Species")