CallierSequential: Create Sequential Color Palettes with Callier Center Colors

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

Description

CallierSequential() creates a sequential color palette of tints of one of the primary Callier Center colors (solar orange, space blue, or callier gray).

Usage

CallierSequential(steps = 3, hue = "orange", lightest = 0.85,
  direction = "increasing")

Arguments

steps	An integer or character vector. Default is 3. If steps is an integer, it only controls the number of tints in the palette. If steps is a character vector, it should correspond exhaustively to the levels of the variable that is mapped onto the palette.
hue	A character string that is matched by either 'or' (orange), 'bl' (blue), or 'gr' (gray). Default is 'orange'.
lightest	A numeric between 0 and 1 that denotes the lightness of the lightest tint in the palatte. Values closer to 0 are darker; those closer to 1 are lighter. Default is 0.85.
direction	A character string that is matched by either 'inc' (increasing) or 'dec' (decreasing). Default is 'increasing'.

Details

A sequential color palette is well suited to ordered data whose values progress from low to high. The look of a sequential palette is dominated by steps that share a common hue and saturation, but differ in terms of lightness. Hence, a sequential palette is a sequence of tints that progress from lightest to darkest, with light colors corresponding to low data values and dark colors corresponding to high data values.

The primary Callier Center color whose hue matches the hue argument anchors the palette and is the darkest tint in the palette. The other tints in the palette share the same hue and saturation as this anchor color, but differ in terms of lightness, in the HSL (hue-saturation-lightness) color model.

The lightness of the lightest tint in the palette is equal to the lightest argument. The tints that fall between the lightest tint and the anchor are determined by linearly interpolating values between lightest and the lightness-value of the anchor color.

If direction is matched by 'inc' (increasing), then the sequential palette progresses from lighter to darker tints. If direction is matched by 'dec' (decreasing), then the sequential palette progresses from darker to lighter tints.

Value

A character vector of hexadecimal codes for colors in the RGB (red-green-blue) color model. The first hexadecimal code denotes the lightest tint in the palette; the last hexadecimal code denotes the darkest.

See Also

CallierQualitative, CallierDiverging

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