Functions to create color palettes.
The functions are:
rainbowPalette | Contiguous rainbow color palette, |
heatPalette | Contiguous heat color palette, |
terrainPalette | Contiguous terrain color palette, |
topoPalette | Contiguous topo color palette, |
cmPalette | Contiguous cm color palette, |
greyPalette | R's gamma-corrected gray palette, |
timPalette | Tim's Matlab like color palette, |
rampPalette | Color ramp palettes, |
seqPalette | Sequential color brewer palettes, |
divPalette | Diverging color brewer palettes, |
qualiPalette | Qualified color brewer palettes, |
focusPalette | Red, green blue focus palettes, |
monoPalette | Red, green blue mono palettes. |
rainbowPalette(n = 64, ...)
heatPalette(n = 64, ...)
terrainPalette(n = 64, ...)
topoPalette(n = 64, ...)
cmPalette(n = 64, ...) greyPalette(n = 64, ...)
timPalette(n = 64)
rampPalette(n, name = c("blue2red", "green2red", "blue2green",
"purple2green", "blue2yellow", "cyan2magenta"))
seqPalette(n, name = c(
"Blues", "BuGn", "BuPu", "GnBu", "Greens", "Greys", "Oranges",
"OrRd", "PuBu", "PuBuGn", "PuRd", "Purples", "RdPu", "Reds",
"YlGn", "YlGnBu", "YlOrBr", "YlOrRd"))
divPalette(n, name = c(
"BrBG", "PiYG", "PRGn", "PuOr", "RdBu", "RdGy", "RdYlBu", "RdYlGn",
"Spectral"))
qualiPalette(n, name = c(
"Accent", "Dark2", "Paired", "Pastel1", "Pastel2", "Set1", "Set2",
"Set3"))
focusPalette(n, name = c("redfocus", "greenfocus", "bluefocus"))
monoPalette(n, name = c("redmono", "greenmono", "bluemono"))
a character string of color strings
an integer, giving the number of greys or colors to be constructed.
a character string, the name of the color set.
arguments to be passed, see the details section
All Rmetrics' color sets are named as fooPalette, where the
prefix foo denotes the name of the underlying color set.
Palettes for n contiguous colors are implemented in the
grDevices package. To conform with Rmetrics' naming
convention for color palettes we have build wrappers around the
underlying functions. These are the rainbowPalette,
heatPalette, terrainPalette, topoPalette, and
the cmPalette.
Conceptually, all of these functions actually use (parts of) a
line cut out of the 3-dimensional color space, parametrized by the
function hsv(h,s,v,gamma), where gamma=1 for the
fooPalette function, and hence, equispaced hues in RGB
space tend to cluster at the red, green and blue primaries.
Some applications, such as contouring, require a palette of colors
which do not wrap around to give a final color close to the
starting one. To pass additional arguments to the underlying
functions see help(rainbow). With rainbow, the parameters
start and end can be used to specify particular
subranges of hues. Synonym function calls are rainbow,
heat.colors, terrain.colors, topo.colors, and
cm.colors.
grayPalette chooses a series of n gamma-corrected
gray levels. The range of the gray levels can be optionally
monitored through the ... arguments, for details see
help(gray.colors), which is a synonym function call in the
grDevices package.
timPalette creates a color set ranging from blue to red,
and passes through the colors cyan, yellow, and orange. It comes
from the Matlab software, originally used in fluid dynamics
simulations. The function here is a copy from R's contributed
package fields doing a spline interpolation on n=64
color points.
rampPalette creates several color ramps. The function is
implemented from Tim Keitt's contributed R package
colorRamps. Supported through the argument name are
the following color ramps: "blue2red", "green2red",
"blue2green", "purple2green", "blue2yellow",
"cyan2magenta".
The functions seqPalette, divPalette, and
qualiPalette create color sets according to R's contributed
RColorBrewer package. The first letter in the function name
denotes the type of the color set: "s" for sequential palettes,
"d" for diverging palettes, and "q" for qualitative palettes.
Sequential palettes are suited to ordered data that progress from low to high. Lightness steps dominate the look of these schemes, with light colors for low data values to dark colors for high data values. The sequential palettes names are: Blues, BuGn, BuPu, GnBu, Greens, Greys, Oranges, OrRd, PuBu, PuBuGn, PuRd, Purples, RdPu, Reds, YlGn, YlGnBu, YlOrBr, YlOrRd.
Diverging palettes put equal emphasis on mid-range critical values and extremes at both ends of the data range. The critical class or break in the middle of the legend is emphasized with light colors and low and high extremes are emphasized with dark colors that have contrasting hues. The diverging palettes names are: BrBG, PiYG, PRGn, PuOr, RdBu, RdGy, RdYlBu, RdYlGn, Spectral.
Qualitative palettes do not imply magnitude differences between legend classes, and hues are used to create the primary visual differences between classes. Qualitative schemes are best suited to representing nominal or categorical data. The qualitative palettes names are: Accent, Dark2, Paired, Pastel1, Pastel2, Set1, Set2, Set3.
In contrast to the original color brewer palettes, the palettes here are created by spline interpolation from the color variation with the most different values, i.e for the sequential palettes these are 9 values, for the diverging palettes these are 11 values, and for the qualitative palettes these are between 8 and 12 values dependeing on the color set.
The function perfanPalette creates color sets inspired by
R's contributed package Performance Analytics. These color
palettes have been designed to create readable, comparable line
and bar graphs with specific objectives.
Color sets designed to provide focus to the data graphed as the first element. This palette is best used when there is clearly an important data set for the viewer to focus on, with the remaining data being secondary, tertiary, etc. Later elements graphed in diminishing values of gray.
These include color sets for monochrome color displays.