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Make divergent color gradient

Source: R/colorjam-gradient.R
make_jam_divergent.Rd

Make divergent color gradients that may also use jam_linear and jam_divergent

Usage

make_jam_divergent(linear1, linear2 = NULL, lite = TRUE, n = 21, ...)

Arguments

linear1

character input consisting of one of:

  • a single character R color

  • a single character color gradient name

  • a character vector of R colors. When supplying a vector of colors, the order is expected to be from blank to maximum color

linear2

character input consisting of one of:

  • a single character R color

  • NULL in which case the color(s) defined by linear1 are passed to color_complement()

  • a single character color gradient name

  • a character vector of R colors. When supplying a vector of colors, the order is expected to be from blank to maximum color

lite

logical indicating whether the middle color should be lite (white), or when lite=FALSE the middle color will be dark (black). When linear1 or linear2 are provided as a named color gradient, such as "Reds" or "Blues", that gradient is used as-is, even if the gradient is designed with a light (or dark) neutral color, therefore ignoring lite.

n

integer number of final colors to produce. Note that n must be an odd number, in order to preserve the middle color.

...

additional arguments are passed to functions called as needed.

Details

This function is intended for a broad capability to create divergent color gradients. It can take several types of input for each "side" of a divergent gradient, and will apply light (white) or dark (black) middle color as defined.

The types of input recognized:

  • character string indicating a single R color, which is passed to jamba::getColorRamp() in order to create one linear color gradient with the relevant light or dark baseline color.

  • character vector indicating a specific sequence of R colors, also passed to jamba::getColorRamp() to return a single linear color gradient. In this case, the color vector should already include the baseline light (white) or dark (black) color. The order of colors is expected to be from blank color to maximum color.

  • character string indicating the name of a recognized color gradient, which can be from RColorBrewer, viridis, or one of the names in jam_linear.

When a color from jam_linear is provided, the appropriate gradient is used for the corresponding lite or dark baseline color, where lite=TRUE uses jam_linear, and lite=FALSE uses the appropriate half gradient from jam_divergent.

Note that this function does not apply the color gradient to a range of numeric values. For that capability, use col_div_xf() with the color gradient produced by this function.

See also

Other colorjam gradients: col_div_xf(), col_linear_xf(), twostep_gradient()

Examples

jamba::showColors(jam_linear)


jg1 <- make_jam_divergent("royalblue", "orangered")
jamba::showColors(jg1)

showDichromat(jg1)


jg1b <- make_jam_divergent("royalblue", main="Supplied as one color")
jamba::showColors(jg1b)


jg2 <- make_jam_divergent("slateblue", "firebrick", n=21)
jamba::showColors(jg2)

showDichromat(jg2)


jg3 <- make_jam_divergent("slateblue", "firebrick", lite=FALSE, n=21)
jamba::showColors(jg3)

showDichromat(jg3)


# Compare manually assembled Blues-Reds to "RdBu_r"
jg4 <- make_jam_divergent("Blues", "Reds", lite=TRUE, n=21)
jamba::showColors(c(jg4,
   list(RdBu_r=jamba::getColorRamp("RdBu_r", n=21))))


# show "inferno"
jg5 <- make_jam_divergent("inferno", lite=FALSE, n=21, gradientWtFactor=1)
jamba::showColors(jg5)


# Optional ComplexHeatmap
if (jamba::check_pkg_installed("ComplexHeatmap")) {
xseq <- seq(from=-1, to=1, by=0.1);
mseq <- matrix(xseq, ncol=1);
m <- mseq %*% t(mseq);
rownames(m) <- seq_len(nrow(m));
colnames(m) <- seq_len(ncol(m));
hm1 <- ComplexHeatmap::Heatmap(m[,1:10],
   cluster_columns=FALSE,
   cluster_rows=FALSE,
   row_names_side="left",
   border=TRUE,
   heatmap_legend_param=list(
      border="grey10",
      at=seq(from=-1, to=1, by=0.25),
      color_bar="discrete"),
   col=jg3[[1]])

hm2 <- ComplexHeatmap::Heatmap(m[21:1,12:21],
   cluster_columns=FALSE,
   cluster_rows=FALSE,
   border=TRUE,
   heatmap_legend_param=list(
      border=TRUE,
      at=seq(from=-1, to=1, by=0.25),
      color_bar="discrete"),
   col=jg2[[1]])
hm1 + hm2
}
#> Warning: Row names of heatmap 2 are not consistent with the main heatmap (1). It
#> may lead to wrong conclusion of your data. Please double check.