colorlegend: Plot a Color Legend In bamlss: Bayesian Additive Models for Location, Scale, and Shape (and Beyond)

 colorlegend R Documentation

Plot a Color Legend

Description

Function to generate a color legend, the legend may be added to an existing plot or drawn in a separate plotting window.

Usage

```colorlegend(color = NULL, ncol = NULL, x = NULL, breaks = NULL,
pos = "center", shift = 0.02, side.legend = 1L, side.ticks = 1L,
range = NULL, lrange = NULL, width = 0.25, height = 0.05,
scale = TRUE, xlim = NULL, ylim = NULL, plot = NULL, full = FALSE,
add = FALSE, col.border = "black", lty.border = 1L, lwd.border = 1L,
ticks = TRUE, at = NULL, col.ticks = "black", lwd.ticks = 1L,
lty.ticks = 1L, length.ticks = 0.3, labels = NULL,
distance.labels = 0, col.labels = "black", cex.labels = 1L,
digits = 2L, swap = FALSE, symmetric = TRUE, xpd = NULL,
title = NULL, side.title = 2, shift.title = c(0, 0),
cex.title = 1, ...)
```

Arguments

 `color` Character, integer. The colors for the legend, may also be a function, e.g. `colors = heat.colors`. `ncol` Integer, the number of different colors that should be generated if `color` is a function. `x` Numeric, values for which the color legend should be drawn. `breaks` Numeric, a set of breakpoints for the colors: must give one more breakpoint than `ncol`. `pos` Character, numeric. The position of the legend. Either a numeric vector, e.g. `pos = c(0.1, 0.2)` will add the legend at the 10\% point in the x-direction and at the 20\% point in the y-direction of the plotting window, may also be negative, or one of the following: `"bottomleft"`, `"topleft"`, `"topright"`, `"bottomright"`, `"left"`, `"right"`, `"top"`, `"bottom"` and `"center"`. `shift` Numeric, if argument `pos` is a character, `shift` determines the distance of the legend from the plotting box. `side.legend` Integer, if set to `2` the legend will be flipped by 90 degrees. `side.ticks` Integer, if set to `2`, the ticks and labels will be on the opposite site of the legend. `range` Numeric, specifies a range for `x` values for which the legend should be drawn. `lrange` Numeric, specifies the range of legend. `width` Numeric, the width of the legend, if `scale = TRUE` the width is proportional to the x-limits of the plotting window. `height` Numeric, the height of the legend, if `scale = TRUE` the height is proportional to the y-limits of the plotting window. `scale` Logical, if set to `TRUE`, the `width` and `height` of the legend will be calculated proportional to the x- and y-limits of the plotting window. `xlim` Numeric, the x-limits of the plotting window the legend should be added for, numeric vector, e.g., returned from function `range`. `ylim` Numeric, the y-limits of the plotting window the legend should be added for, numeric vector, e.g., returned from function `range`. `plot` Logical, if set to `TRUE`, the legend will be drawn in a separate plotting window. `full` Logical, if set to `TRUE`, the legend will be drawn using the full window range. `add` Logical, if set to `TRUE`, the legend will be added to an existing plot. `col.border` The color of the surrounding border line of the legend. `lty.border` The line type of the surrounding border line of the legend. `lwd.border` The line width of the surrounding border line of the legend. `ticks` Logical, if set to `TRUE`, ticks will be added to the legend. `at` Numeric, specifies at which locations ticks and labels should be added. `col.ticks` The colors of the ticks. `lwd.ticks` The line width of the ticks. `lty.ticks` The line type of the ticks. `length.ticks` Numeric, the length of the ticks as percentage of the `height` or `width` of the colorlegend. `labels` Character, specifies labels that should be added to the ticks. `distance.labels` Numeric, the distance of the labels to the ticks, proportional to the length of the ticks. `col.labels` The colors of the labels. `cex.labels` Text size of the labels. `digits` Integer, the decimal places if labels are numerical. `swap` Logical, if set to `TRUE` colors will be represented in reverse order. `symmetric` Logical, if set to `TRUE`, a symmetric legend will be drawn corresponding to the `+- max(abs(x))` value. `xpd` Sets the `xpd` parameter in function `par`. `title` Character, a title for the legend. `side.title` Integer, `1` or `2`. Specifies where the legend is placed, either on top if `side.title = 1` or at the bottom if `side.title = 2`. `shift.title` Numeric vector of length 2. Specifies a possible shift of the title in either x- or y-direction. `cex.title` Text size for the title. `...` Other graphical parameters to be passed to function `text`.

Value

A named `list` with the colors generated, the breaks and the function `map`, which may be used for mapping of `x` values to the colors specified in argument `colors`, please see the examples below.

Examples

```## Play with colorlegend.
colorlegend()
colorlegend(side.legend = 2)
colorlegend(side.legend = 2, side.ticks = 2)
colorlegend(height = 2)
colorlegend(width = 1, height = 0.8, scale = FALSE,
pos = c(0, 0.2), length.ticks = 0.5)
colorlegend(color = heat.colors, ncol = 9)
colorlegend(color = heat.colors, ncol = 9, swap = TRUE)
colorlegend(pos = "bottomleft")
colorlegend(pos = "topleft")
colorlegend(pos = "topright")
colorlegend(pos = "bottomright")

## Take x values for the color legend.
x <- runif(100, -2, 2)
colorlegend(color = diverge_hcl, x = x)
colorlegend(color = diverge_hcl, x = x, at = c(-1.5, 0, 1.5))
colorlegend(color = diverge_hcl, x = x, at = c(-1.5, 0, 1.5),
labels = c("low", "middle", "high"))
colorlegend(color = rainbow_hcl, x = x, at = c(-1.5, 0, 1.5),
labels = c("low", "middle", "high"), length.ticks = 1.5)
colorlegend(color = heat_hcl, x = x, at = c(-1.5, 0, 1.5),
labels = c("low", "middle", "high"), length.ticks = 1.5,
lwd.border = 2, lwd.ticks = 2, cex.labels = 1.5, font = 2)
colorlegend(color = topo.colors, x = x, at = c(-1.5, 0, 1.5),
labels = c("low", "middle", "high"), length.ticks = 1.5,
lwd.border = 2, lwd.ticks = 2, cex.labels = 1.5, font = 2,
col.border = "green3", col.ticks = c(2, 5, 2),
col.labels = c(6, 4, 3))
colorlegend(color = diverge_hsv, x = x, at = c(-1.5, 0, 1.5),
labels = c("low", "middle", "high"), length.ticks = 1.5,
lwd.border = 2, lwd.ticks = 2, cex.labels = 1.5, font = 2,
col.border = "green3", col.ticks = c(2, 5, 2),
col.labels = c(6, 4, 3), lty.border = 2, lty.ticks = c(2, 3, 2))
colorlegend(color = diverge_hsv, x = x, at = c(-1.5, 0, 1.5),
labels = c("low", "middle", "high"), length.ticks = 1.5,
lwd.border = 2, lwd.ticks = 2, cex.labels = 1.5, font = 2,
col.border = "green3", col.ticks = c(2, 5, 2),
col.labels = c(6, 4, 3), lty.border = 2, lty.ticks = c(2, 3, 2),
ncol = 3)
colorlegend(color = c("red", "white", "red"), x = x, at = c(-1.5, 0, 1.5),
labels = c("low", "middle", "high"), length.ticks = 1.5,
lwd.border = 2, lwd.ticks = 2, cex.labels = 1.5, font = 2,
col.border = "green3", col.ticks = c(2, 5, 2),
col.labels = c(6, 4, 3), lty.border = 2, lty.ticks = c(2, 3, 2),
ncol = 3, breaks = c(-2, -1, 1, 2))
colorlegend(color = diverge_hcl, x = x, range = c(-3, 3))
colorlegend(color = diverge_hcl, x = x, range = c(-3, 3), lrange = c(-6, 6))

## Combine plot with color legend.
n <- 100
x <- y <- seq(-3, 3, length.out = n)
z <- outer(sin(x), cos(x))
pal <- colorlegend(color = diverge_hcl, x = z, plot = FALSE)
par(mar = c(4.1, 4.1, 1.1, 1.1))
layout(matrix(c(1, 2), nrow = 1), widths = c(1, 0.3))
image(x = x, y = y, z = z, col = pal\$colors, breaks = pal\$breaks)
par(mar = c(4.1, 0.1, 1.1, 3.1))
colorlegend(color = diverge_hcl, x = z, plot = TRUE, full = TRUE,
side.legend = 2, side.ticks = 2)
par(op)

## Another example with different plot.
n <- 50
x <- sin(seq(-3, 3, length.out = n))
pal <- colorlegend(color = diverge_hcl, x = x, plot = FALSE)