Assign plotting size (cex values) to a vector

assign_cex() maps the character expansion (size). The cex is most commonly used for points and text, and humans perceive the area of points (not their radius), so this provides for optimal perception. The argument area ensures that a value of 0 is mapped to a size of 0; assign_cex_binned() is a binned version, and assign_cex_d() assigns cex values to discrete values.

Usage

assign_cex(x, range = c(0.25, 2), area = FALSE)

assign_cex_binned(x, range = c(0.25, 2), breaks = 5, area = FALSE)

assign_cex_d(x, values = NULL, range = c(0.25, 2))

legend_cex(
  x,
  range = c(0.25, 2),
  breaks = 5,
  values = NULL,
  area = FALSE,
  position = "topright",
  pch = 16,
  ...
)

Arguments

x: vector
range: numeric 2-element vector. Output range of cex values. Minimum value must be greater than 0.
area: logical. Whether cex should be proportional to the area (TRUE) or the radius (FALSE, the default) of the plotting character.
breaks: integer giving the desired number of intervals. Non-integer values are rounded down.
values: numeric. cex values to manually assign to x. Must be at least the number of unique values in x.
position: Legend position. Either a two-column vector of the x and y coordinates, or a keyword from the list "bottomright", "bottom", "bottomleft", "left", "topleft", "top", "topright", "right" and "center".
pch: plotting character to be used in legend.
...: arguments passed to graphics::legend()

Value

numeric vector

Details

The character expansion cex is a number indicating the amount by which plotting text and symbols should be scaled relative to the default. 1=default, 1.5 is 50% larger, 0.5 is 50% smaller, etc.

Examples

set.seed(20250411)

# example for continuous colors:
x <- rvmf(100, mu = Line(120, 50), k = 5)
key <- runif(100)
plot(x, cex = assign_cex(key), grid.params = list(guides = FALSE))
legend_cex(key, position = 'topright', area = TRUE)