Add a density curve to a plot

For example, a plot a normal density over a histogram of conditional weighted residuals.

add_density(fun = dnorm, col = .ggblue, lwd = 1.5, lty = 2, ...)

layer_dnorm(x, sd = 1, mean = 0, ...)

Arguments

fun	passed to ggplot2::stat_function
col	passed to ggplot2::stat_function
lwd	passed to ggplot2::stat_function
lty	passed to ggplot2::stat_function
...	passed to ggplot2::stat_function
x	a ggplot object to which the density line will be added
sd	passed to stats::dnorm
mean	passed to stats::dnorm