Tricolore {tricolore}

Ternary Balance Color Scale

Description

Color-code three-part compositions with a ternary balance color scale and return a color key.

Usage

Tricolore(
  df,
  p1,
  p2,
  p3,
  center = rep(1/3, 3),
  breaks = ifelse(identical(center, rep(1/3, 3)), 4, Inf),
  hue = 0.2,
  chroma = 0.7,
  lightness = 0.8,
  contrast = 0.4,
  spread = 1,
  legend = TRUE,
  show_data = TRUE,
  show_center = ifelse(identical(center, rep(1/3, 3)), FALSE, TRUE),
  label_as = ifelse(identical(center, rep(1/3, 3)), "pct", "pct_diff"),
  crop = FALSE,
  input_validation = TRUE
)

Arguments

df

Data frame of compositional data.

p1

Column name for variable in df giving first proportion of ternary composition (string).

p2

Column name for variable in df giving second proportion of ternary composition (string).

p3

Column name for variable in df giving third proportion of ternary composition (string).

center

Ternary coordinates of the color scale center. (default = 1/3,1/3,1/3). NA puts center over the compositional mean of the data.

breaks

Number of per-axis breaks in the discrete color scale. An integer >1. Values above 99 imply no discretization.

hue

Primary hue of the first ternary element (0 to 1).

chroma

Maximum possible chroma of mixed colors (0 to 1).

lightness

Lightness of mixed colors (0 to 1).

contrast

Lightness contrast of the color scale (0 to 1).

spread

The spread of the color scale. Choose values > 1 to focus the color scale on the center.

legend

Should a legend be returned along with the colors? (default=TRUE)

show_data

Should the data be shown on the legend? (default=TRUE)

show_center

Should the center be shown on the legend? (default=FALSE if center is at c(1/3, 1/3, 1/3), otherwise TRUE)

label_as

"pct" for percent-share labels or "pct_diff" for percent-point-difference from center labels. (default='pct' if center is at c(1/3, 1/3, 1/3), otherwise 'pct_diff')

crop

Should the legend be cropped to the data? (default=FALSE)

input_validation

Should the function arguments be validated? (default=TRUE)

Value

• legend=FALSE: A vector of rgbs hex-codes representing the ternary balance scheme colors.

• legend=TRUE: A list with elements "rgb" and "key".

Examples

P <- as.data.frame(prop.table(matrix(runif(3^6), ncol = 3), 1))
Tricolore(P, 'V1', 'V2', 'V3')