tidyterra (version 0.3.0)

scale_fill_whitebox: Gradient fill scales from WhiteboxTools color schemes

Description

Implementation of the gradient palettes provided by WhiteboxTools. Three fill scales are provided:

• scale_fill_whitebox_d(): For discrete values.

• scale_fill_whitebox_c(): For continuous values.

• scale_fill_whitebox_b(): For binning continuous values.

Additionally, a color palette whitebox.colors() is provided. See also grDevices::terrain.colors() for details.

Usage

scale_fill_whitebox_d(palette = "high_relief", ..., alpha = 1, direction = 1)
scale_fill_whitebox_c(
  palette = "high_relief",
  ...,
  alpha = 1,
  direction = 1,
  na.value = NA,
  guide = "colourbar"
)
scale_fill_whitebox_b(
  palette = "high_relief",
  ...,
  alpha = 1,
  direction = 1,
  na.value = NA,
  guide = "coloursteps"
)
whitebox.colors(n, palette = "high_relief", alpha = 1, rev = FALSE)

Value

The corresponding ggplot2 layer with the values applied to the fill aesthetics.

Arguments

palette

A valid palette name. The name is matched to the list of available palettes, ignoring upper vs. lower case. Values available are: "atlas", "high_relief", "arid", "soft", "muted", "purple", "viridi", "gn_yl", "pi_y_g", "bl_yl_rd", "deep".

...

Other arguments passed on to discrete_scale(), continuous_scale(), or binned_scale to control name, limits, breaks, labels and so forth.

alpha

The alpha transparency, a number in [0,1], see argument alpha in hsv.

direction

Sets the order of colors in the scale. If 1, the default, colors are ordered from darkest to lightest. If -1, the order of colors is reversed.

na.value

Missing values will be replaced with this value.

guide

A function used to create a guide or its name. See guides() for more information.

n

the number of colors (\(\ge 1\)) to be in the palette.

rev

logical indicating whether the ordering of the colors should be reversed.

See Also

terra::plot(), ggplot2::scale_fill_viridis_c()

Other gradient scales and palettes for hypsometry: scale_fill_cross_blended, scale_fill_hypso, scale_fill_terrain, scale_fill_wiki

Examples

# \donttest{
filepath <- system.file("extdata/volcano2.tif", package = "tidyterra")

library(terra)
volcano2_rast <- rast(filepath)

# Palette
plot(volcano2_rast, col = whitebox.colors(100))

library(ggplot2)
ggplot() +
  geom_spatraster(data = volcano2_rast) +
  scale_fill_whitebox_c()

# Binned
ggplot() +
  geom_spatraster(data = volcano2_rast) +
  scale_fill_whitebox_b(breaks = seq(70, 200, 10), palette = "atlas")

# With discrete values
factor <- volcano2_rast %>% mutate(cats = cut(elevation,
  breaks = c(100, 120, 130, 150, 170, 200),
  labels = c(
    "Very Low", "Low", "Average", "High",
    "Very High"
  )
))


ggplot() +
  geom_spatraster(data = factor, aes(fill = cats)) +
  scale_fill_whitebox_d(na.value = "gray10", palette = "soft")
# }

# Display all the whitebox palettes

pals <- c(
  "atlas", "high_relief", "arid", "soft", "muted", "purple",
  "viridi", "gn_yl", "pi_y_g", "bl_yl_rd", "deep"
)

# Helper fun for plotting

ncols <- 128
rowcol <- grDevices::n2mfrow(length(pals))

opar <- par(no.readonly = TRUE)
par(mfrow = rowcol, mar = rep(1, 4))

for (i in pals) {
  image(
    x = seq(1, ncols), y = 1, z = as.matrix(seq(1, ncols)),
    col = whitebox.colors(ncols, i), main = i,
    ylab = "", xaxt = "n", yaxt = "n", bty = "n"
  )
}
par(opar)