The adjust_luminance()
function can brighten or darken a palette of colors
by an arbitrary number of steps, which is defined by a real number between
-2.0 and 2.0. The transformation of a palette by a fixed step in this
function will tend to apply greater darkening or lightening for those colors
in the midrange compared to any very dark or very light colors in the input
palette.
adjust_luminance(colors, steps)
A vector of color values.
Color vector
vector<character>
// required
This is the vector of colors that will undergo an adjustment in luminance.
Each color value provided must either be a color name (in the set of colors
provided by grDevices::colors()
) or a hexadecimal string in the form of
"#RRGGBB" or "#RRGGBBAA".
Adjustment level
scalar<numeric|integer>(-2>=val>=2)
// required
A positive or negative factor by which the luminance of colors in the
colors
vector will be adjusted. Must be a number between -2.0
and
2.0
.
Get a palette of 8 pastel colors from the RColorBrewer package.
pal <- RColorBrewer::brewer.pal(8, "Pastel2")
Create lighter and darker variants of the base palette (one step lower, one step higher).
pal_darker <- pal |> adjust_luminance(-1.0)
pal_lighter <- pal |> adjust_luminance(+1.0)
Create a tibble and make a gt table from it. Color each column in order
of increasingly darker palettes (with data_color()
).
dplyr::tibble(a = 1:8, b = 1:8, c = 1:8) |>
gt() |>
data_color(
columns = a,
colors = scales::col_numeric(
palette = pal_lighter,
domain = c(1, 8)
)
) |>
data_color(
columns = b,
colors = scales::col_numeric(
palette = pal,
domain = c(1, 8)
)
) |>
data_color(
columns = c,
colors = scales::col_numeric(
palette = pal_darker,
domain = c(1, 8)
)
)
8-9
v0.2.0.5
(March 31, 2020)
This function can be useful when combined with the data_color()
function's
palette
argument, which can use a vector of colors or any of the col_*
functions from the scales package (all of which have a palette
argument).
Other helper functions:
cell_borders()
,
cell_fill()
,
cell_text()
,
currency()
,
default_fonts()
,
escape_latex()
,
from_column()
,
google_font()
,
gt_latex_dependencies()
,
html()
,
md()
,
nanoplot_options()
,
pct()
,
px()
,
random_id()
,
row_group()
,
stub()
,
system_fonts()
,
unit_conversion()