Plot only legend of plot function

Plot only legend of plot function

gglegend(fn)

Arguments

fn

this value is passed directly to an empty wrap call. Please see ?wrap for more details.

Value

a function that when called with arguments will produce the legend of the plotting function supplied.

Examples

# Small function to display plots only if it's interactive
p_ <- GGally::print_if_interactive

# display regular plot
p_(ggally_points(iris, ggplot2::aes(Sepal.Length, Sepal.Width, color = Species)))

# Make a function that will only print the legend
points_legend <- gglegend(ggally_points)
p_(points_legend(iris, ggplot2::aes(Sepal.Length, Sepal.Width, color = Species)))

# produce the sample legend plot, but supply a string that 'wrap' understands
same_points_legend <- gglegend("points")
identical(
  attr(attr(points_legend, "fn"), "original_fn"),
  attr(attr(same_points_legend, "fn"), "original_fn")
)
#> [1] TRUE

# Complicated examples
custom_legend <- wrap(gglegend("points"), size = 6)
p_(custom_legend(iris, ggplot2::aes(Sepal.Length, Sepal.Width, color = Species)))


# Use within ggpairs
pm <- ggpairs(
  iris, 1:2,
  mapping = ggplot2::aes(color = Species),
  upper = list(continuous = gglegend("points"))
)
p_(pm)


# Place a legend in a specific location
pm <- ggpairs(iris, 1:2, mapping = ggplot2::aes(color = Species))
# Make the legend
pm[1, 2] <- points_legend(iris, ggplot2::aes(Sepal.Width, Sepal.Length, color = Species))
p_(pm)