Plot Rendering Options

Create a set of options controlling how plot inputs (ggplot objects, plotting functions and recorded plots) are rendered to PNG before being compared by compare_images(), expect_images_match(), expect_images_differ() and expect_snapshot_image().

Usage

plot_options(width = 7, height = 5, units = "in", res = 96, bg = "white")

Arguments

width, height

Plot dimensions, in units. Default is 7 x 5 inches.

units

Units for width and height: one of "in", "cm", "mm" or "px". Default is "in".

res

Resolution in pixels per inch. Default is 96.

bg

Background colour. Default is "white".

Value

A list of class odiffr_plot_options, to be passed as the plot_options argument.

Details

Plots are rendered with ragg::agg_png() when the ragg package is installed (recommended: its output is consistent across platforms), and with grDevices::png() otherwise. When comparing a plot against a stored baseline PNG, render it with the same options (and the same graphics device) that were used to create the baseline, or the comparison will fail with a layout difference.

See also

compare_images(), expect_snapshot_image()

Examples

plot_options(width = 4, height = 3, res = 72)
#> <odiffr plot options> 4 x 3 in, 72 dpi, bg = white