Plot styling for the package's plot methods

Every plot() method in the package draws with base graphics and the same small set of style choices, which these functions expose. blpal() returns colour-blind-safe palettes: "okabe" (the Okabe-Ito categorical set), "diverging" (blue, grey, orange), "sequential" (light to dark blue) and "grey". plotopt() sets the defaults every method uses, for the session: palette, grid, cex, las and bg. Each method also takes main, col (which overrides the palette), palette and ... passed to the underlying base-graphics call, so a single plot can be changed without changing the session. Use blpal() also to colour your own plots so they match the package's.

Usage

blpal(name = c("okabe", "diverging", "sequential", "grey"), n = NULL)

plotopt(...)

Arguments

name

Character scalar, the palette: "okabe" (the default), or one of "diverging", "sequential" and "grey".

n

Integer scalar or NULL (the default: the palette's own colours). The number of colours wanted; "okabe" and "grey" recycle, "sequential" and "diverging" interpolate.

...

For plotopt(), named options to set: palette (a palette name), grid (logical, draw grid lines), cex (numeric text and symbol size), las (axis label orientation, as in par()), bg (background colour) and panel (the plot region's fill behind white grid lines, NA for none). With no arguments, the current values are returned.

Value

blpal(): a character vector of hexadecimal colours. plotopt(): a named list of the six options in force (after the change), invisibly when setting.

Details

The palettes: "okabe" is the eight-colour set of Okabe and Ito (2008), distinguishable under the common forms of colour-vision deficiency. "diverging" has three anchors (blue #2166AC, grey #8C8C8C, orange-red #D6604D) and is used for changes (decrease, no change, increase). The palette "sequential" has five blues from light to dark; "grey" five greys from dark to light. With n given, "okabe" and "grey" repeat their colours (rep_len()) and "diverging" and "sequential" are interpolated with grDevices::colorRampPalette().

The session options are stored in options(rmoriebricklayer.plot); the defaults are palette = "okabe", grid = TRUE, cex = 1, las = 1, bg = "white" and panel = "#EEF1F6". Setting some options keeps the others.

Text is drawn at the session cex. Titles, axis titles, row labels and keys are made smaller to fit a small device, but never below 0.6 of that size, so that they stay readable; for larger text set, for example, plotopt(cex = 1.2), and for a table with many rows use a taller device.

Errors: an unknown palette name; n not a positive whole number; an option name other than the six above, or an unnamed value; an unknown palette option.

References

Okabe, M. and Ito, K. (2008). Color Universal Design (CUD): how to make figures and presentations that are friendly to colorblind people. jfly.uni-koeln.de/color

Examples

blpal("okabe", 3)
#> [1] "#0072B2" "#D55E00" "#009E73"
# plotopt() returns the options in force, so keep them before a change
old <- plotopt()
plotopt(palette = "grey", grid = FALSE)
plotopt(palette = old$palette, grid = old$grid)

# an interpolated sequential scale, shown as swatches
cols <- blpal("sequential", 7)
barplot(
  rep(1, 7),
  col = cols,
  border = NA,
  axes = FALSE,
  names.arg = cols,
  las = 2,
  cex.names = 0.6
)


# the same palette in a base plot of your own
plot(1:8, pch = 19, cex = 3, col = blpal("okabe"))


# names are checked
try(blpal("viridis"))
#> Error : blpal: `name` must be one of "okabe", "diverging", "sequential", "grey", not "viridis"
try(plotopt(colour = "red"))
#> Error : plot options are palette, grid, cex, las, bg, panel