CallierQualitative: Create Qualitative Color Palettes with Callier Center Colors

In patrickreidy/callierr: Color Palettes and Scales for the Callier Center for Communication Disorders

Description

CallierQualitative() creates a qualitative color palette based on the primary, secondary, and tertiary Callier Center colors, in the following order of precedence: solar orange, space blue, callier gray, spark orange, stratos blue, sky blue, eco green, sapling green, and seedling green.

Usage

CallierQualitative(steps = 3)

Arguments

steps

An integer or character vector. Default is 3.

Details

A qualitative color palette does not imply magnitude differences between levels in the data. As such, a qualitative palette is best suited to representing nominal or categorical data.

A qualitative color palette is most effective when hues are used to signal visual differences between levels in the data; hence, a palette that uses only the three primary Callier Center colors is thus quite effective. But the effectiveness of the Callier Center colors as a qualitative palette diminishes when the secondary Callier Center colors are used: the secondary colors all repeat hues (orange or blue) that are already represented in the primary Callier Center colors.

If steps is a character vector, its entries should correspond exhaustively to the levels of the variable that is being mapped onto the color palette. The number of colors in the returned palette is equal to the length of steps. The mapping from steps onto Callier Center colors preserves the order of elements in steps and the order of precedence in the Callier Center colors: i.e., the first element of steps is mapped to solarOrange; the second element, to spaceBlue; and so on.

If steps is an integer, then it controls only the number of Callier Center colors in the returned palette. The mapping from the levels of the data variable onto Callier Center colors is inherited from however the data levels are ordered: If the variable is an ordered factor, then the data levels are mapped in that order. If the variable is unordered, then the data levels are mapped alphabetically.

Value

A character vector of hexadecimal codes for the Callier Center colors. If steps is greater than the number of Callier Center colors (9), then NULL is returned; hence, this palette cannot be used for qualitative data with more than 9 levels.

See Also

CallierSequential, CallierDiverging

patrickreidy/callierr documentation built on May 24, 2019, 8:22 p.m.