legend.scale {autoimage} | R Documentation |
Color scale legend
Description
legend.scale
plots a color gradient with an associated
quantitative scale.
Usage
legend.scale(
zlim,
col = colorspace::sequential_hcl(n = 12, palette = "Viridis"),
horizontal = TRUE,
breaks,
axis.args
)
Arguments
zlim |
A two-dimensional vector containing the minimum and maximum quantitative limits, respectively, for the color scale. |
col |
A vector of colors used for the color scale. Typically,
this is a gradient of colors. The default is the 12 colors
generated by |
horizontal |
A logical value indicating whether the legend
should extend horizontally ( |
breaks |
The sequence of values defining the partition of
|
axis.args |
A list of named elements corresponding to the
arguments of the |
Details
The length of the col
vector indicates the number of
partitions for the quantitative range.
References
The code for this function is derived from the
internals of the image.plot
function
written by Doug Nychka and from the image.scale
function
written by Marc Taylor and discussed at
https://menugget.blogspot.com/2013/12/new-version-of-imagescale-function.html.
See Also
Examples
# default horizontal scale
legend.scale(c(0, 1))
# default vertical scale
legend.scale(c(0, 1), horizontal = FALSE)
# different color scheme with 24 colors
legend.scale(c(0, 1), col = cm.colors(24))
# irregular color breaks
legend.scale(c(0, 1), col = heat.colors(4),
breaks = c(0, 0.5, 0.75, 0.875, 1))
# irregular color breaks with modified ticks and vertical
# orientation of labels
legend.scale(c(0, 1), col = heat.colors(4),
breaks = c(0, 0.5, 0.75, 0.875, 1),
axis.args = list(at = c(0, 0.5, 0.75, 0.875, 1), las = 2))
# change size of axis labels
legend.scale(c(0, 1), axis.args = list(cex.axis = 2))
# change color of axis labels and ticks
blue.axes <- list(col.axis = "blue", col.ticks = "blue")
legend.scale(c(0, 1), axis.args = blue.axes)
# log base 10 values with colors labeled on original scale
options(scipen = 2)
log.axis <- list(at = 0:6, labels = 10^(0:6), las = 2)
legend.scale(c(0, 6), col = heat.colors(6), axis.args = log.axis)