DescTools (version 0.99.18)

ColorLegend: Add a ColorLegend to a Plot

Description

Add a color legend, an image of a sequence of colors, to a plot.

Usage

ColorLegend(x, y = NULL, cols = rev(heat.colors(100)), labels = NULL, width = NULL, height = NULL, horiz = FALSE, xjust = 0, yjust = 1, inset = 0, border = NA, frame = NA, cntrlbl = FALSE, adj = ifelse(horiz, c(0.5, 1), c(1, 0.5)), cex = 1, ...)

Arguments

x
the left x-coordinate to be used to position the colorlegend. See 'Details'.
y
the top y-coordinate to be used to position the colorlegend. See 'Details'.
cols
the color appearing in the colorlegend.
labels
a vector of labels to be placed at the right side of the colorlegend.
width
the width of the colorlegend.
height
the height of the colorlegend.
horiz
logical indicating if the colorlegend should be horizontal; default FALSE means vertical alignment.
xjust
how the colorlegend is to be justified relative to the colorlegend x location. A value of 0 means left justified, 0.5 means centered and 1 means right justified.
yjust
the same as xjust for the legend y location.
inset
inset distance(s) from the margins as a fraction of the plot region when colorlegend is placed by keyword.
border
defines the bordor color of each rectangle. Default is none (NA).
frame
defines the bordor color of the frame around the whole colorlegend. Default is none (NA).
cntrlbl
defines, whether the labels should be printed in the middle of the color blocks or start at the edges of the colorlegend. Default is FALSE, which will print the extreme labels centered on the edges.
adj
text alignment, horizontal and vertical.
cex
character extension for the labels, default 1.0.
...
further arguments are passed to the function text.

Details

The labels are placed at the right side of the colorlegend and are reparted uniformly between y and y - height.

The location may also be specified by setting x to a single keyword from the list "bottomright", "bottom", "bottomleft", "left", "topleft", "top", "topright", "right" and "center". This places the colorlegend on the inside of the plot frame at the given location. Partial argument matching is used. The optional inset argument specifies how far the colorlegend is inset from the plot margins. If a single value is given, it is used for both margins; if two values are given, the first is used for x- distance, the second for y-distance.

See Also

legend, FindColor, BubbleLegend

Examples

Run this code
plot(1:15,, xlim=c(0,10), type="n", xlab="", ylab="", main="Colorstrips")

# A
ColorLegend(x="right", inset=0.1, labels=c(1:10))

# B: Center the labels
ColorLegend(x=1, y=9, height=6, col=colorRampPalette(c("blue", "white", "red"), 
  space = "rgb")(5), labels=1:5, cntrlbl = TRUE)

# C: Outer frame
ColorLegend(x=3, y=9, height=6, col=colorRampPalette(c("blue", "white", "red"), 
  space = "rgb")(5), labels=1:4, frame="grey")

# D
ColorLegend(x=5, y=9, height=6, col=colorRampPalette(c("blue", "white", "red"),
  space = "rgb")(10), labels=sprintf("%.1f",seq(0,1,0.1)), cex=0.8)
  
# E: horizontal shape
ColorLegend(x=1, y=2, width=6, height=0.2, col=rainbow(500), labels=1:5,horiz=TRUE)

# F
ColorLegend(x=1, y=14, width=6, height=0.5, col=colorRampPalette(
  c("red","yellow","green","blue","black"), space = "rgb")(100), horiz=TRUE)

# G
ColorLegend(x=1, y=12, width=6, height=1, col=colorRampPalette(c("red","yellow",
  "green","blue","black"), space = "rgb")(10), horiz=TRUE, border="black")

text(x = c(8,0.5,2.5,4.5,0.5,0.5,0.5)+.2, y=c(14,9,9,9,2,14,12), LETTERS[1:7], cex=2)

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