treepalette: Obtain hierarchical color palettes (Tree Colors)

Description

Obtain hierarchical color palettes, either the so-called Tree Colors from the HCL color space model, or by using an existing color palette. The former method, which is recommended, is used by default in treemap (type "index") and treegraph. Use treecolors to experiment with this method.

Usage

treepalette(dtf, index = names(dtf), method = "HCL", palette = NULL, palette.HCL.options, return.parameters = TRUE, prepare.dat = TRUE)

Arguments

dtf

a data.frame or data.table. Required.

index

the index variables of dtf

method

used method: either "HCL" (recommended), which is based on the HCL color space model, or "HSV", which uses the argument palette.

palette

color palette, which is only used for the HSV method

palette.HCL.options

list of options to obtain Tree Colors from the HCL space (when palette="HCL"). This list contains:

hue_start:: number between 0 and 360 that determines the starting hue value (default: 30)
hue_end:: number between hue_start and hue_start + 360 that determines the ending hue value (default: 390)
hue_perm:: boolean that determines whether the colors are permuted such that adjacent levels get more distinguishable colors. If FALSE, then the colors are equally distributed from hue_start to hue_end (default: TRUE)
hue_rev:: boolean that determines whether the colors of even-numbered branched are reversed (to increase discrimination among branches)
hue_fraction:: number between 0 and 1 that determines the fraction of the hue circle that is used for recursive color picking: if 1 then the full hue circle is used, which means that the hue of the colors of lower-level nodes are spread maximally. If 0, then the hue of the colors of lower-level nodes are identical of the hue of their parents. (default: .5)
chroma:: chroma value of colors of the first-level nodes, that are determined by the first index variable (default: 60)
luminance:: luminance value of colors of the first-level nodes, i.e. determined by the first index variable (default: 70)
chroma_slope:: slope value for chroma of the non-first-level nodes. The chroma values for the second-level nodes are chroma+chroma_slope, for the third-level nodes chroma+2*chroma_slope, etc. (default: 5)
luminance_slope:: slope value for luminance of the non-first-level nodes (default: -10)

For "depth" and "categorical" types, only the first two items are used. Use treecolors to experiment with these parameters.

return.parameters

should a data.frame with color values and parameter options be returned (TRUE), or just the vector of color values (FALSE)?

prepare.dat

data is by default preprocessed, except for interal use

Value

Either a vector of colors, or a data.frame is return (see return.parameters).