Declare a color palette preference

Convenience wrappers around pipeline$define_preference that declare a palette preference in the "graphics" domain, validate it against the matching table in rave-colormaps, and resolve the stored palette name to the colors themselves. Use define_preference_discrete_colormap for categorical variables and define_preference_continuous_colormap for numeric heat maps.

Re-declaring is cheap and safe: the stored preference metadata is rewritten only when the declaration actually changes, and a user's chosen palette is never overwritten.

Usage

define_preference_discrete_colormap(
  pipeline,
  default = "default",
  verbose = TRUE,
  force = FALSE
)

define_preference_continuous_colormap(
  pipeline,
  default = "default",
  verbose = TRUE,
  force = FALSE
)

Arguments

pipeline

a PipelineTools instance

default

palette name used whenever the preference is unset; must be a valid name for the corresponding table

verbose

whether to emit trace-level logs; default is true

force

whether to re-declare even when the stored declaration is already current; default is false. See define_preference in PipelineTools: declaring is skipped when the recorded version is up to date, so these helpers can be called on every launch without touching the disk. Set to TRUE only while developing

Value

Invisibly, a list with the stored palette name (preference_value), whether the declaration was rewritten (metadata_updated), and the preference metadata. Read the colors themselves with pipeline$use_preference, which runs the declared getter

Examples

library(ravepipeline)
if(interactive() && length(pipeline_list()) > 0) {
  pipeline <- pipeline("power_explorer")

  res <- define_preference_discrete_colormap(pipeline)
  res$preference_value    # the palette name

  # the colors, plus the name they came from
  colors <- pipeline$use_preference("discrete_colormap")
  attr(colors, "preference_value")

  pipeline$use_preference("discrete_colormap", value = "tab10")
}