huePosition: Munsell Hue Reference and Position Searching

In aqp: Algorithms for Quantitative Pedology

Munsell Hue Reference and Position Searching

Description

The 40 Munsell hues are typically arranged from 5R to 2.5R moving clock wise on the unit circle. This function matches a vector of hues to positions on that circle, with options for setting a custom origin or search direction.

This function is fully vectorized.

Usage

huePosition(
  x,
  returnHues = FALSE,
  includeNeutral = FALSE,
  origin = "5R",
  direction = c("cw", "ccw")
)

Arguments

x	character vector of hues, e.g. c('10YR', '5YR'), optional if returnHues = TRUE
returnHues	logical, should the full set of Munsell hues be returned? See details.
includeNeutral	logical, add 'N' to the end of the full set of Munsell hues
origin	hue to be used as the starting point for position searches (position 1)
direction	indexing direction, should be cw (clock wise) or ccw (counter-clock wise)

Value

A vector of integer hue positions is returned, of the same length and order as x. If returnHues = TRUE, then all hue names and ordering are returned and x is ignored.

Author(s)

D.E. Beaudette

References

• Soil Survey Technical Note 2 wayback machine URL

• Munsell book of color. 1976. Macbeth, a Division of Kollmorgen Corp., Baltimore, MD.

See Also

colorContrast, huePositionCircle

Examples

# get hue ordering for setting levels of a factor
huePosition(returnHues = TRUE)

# get hue ordering including N (neutral)
huePosition(returnHues = TRUE, includeNeutral = TRUE)

# get position of the '10YR' hue, relative to standard origin of '5R'
# should be 7
huePosition(x = '10YR')

# get position of the '10YR' hue, relative to standard origin of '5YR'
# should be 3
huePosition(x = '10YR', origin = '5YR')

# visualize
op <- par(mar = c(0, 0, 0, 0), fg = 'white', bg = 'black')

huePositionCircle(huePosition(returnHues = TRUE, origin = '5YR'))

par(op)

aqp documentation built on Oct. 19, 2024, 5:06 p.m.