simulateColor: Simulate Soil Colors

In ncss-tech/aqp: Algorithms for Quantitative Pedology

Simulate Soil Colors

Description

Simulate plausible soil colors based on several possible parameterization of a "range in characteristics" (RIC). Soil color RIC can be specified by a list of parameters:

• soil color proportions, as output from aggregateColor() – method = 'proportions'

• most likely Munsell color, CIE2000 threshold, and vector of acceptable hues – method = 'dE00'

• data.frame of Munsell hue, value, and chroma representing observed soil colors – method = 'mvnorm'

Usage

simulateColor(
  method = c("dE00", "proportions", "mvnorm"),
  n,
  parameters,
  SPC = NULL
)

Arguments

method	simulation method, see details
n	number of simulated colors per group
parameters	a list, format depends on method: proportions: output from aggregateColor() dE00: formatted as list(m = '7.5YR 3/3', thresh = 5, hues = c('7.5YR')) mvnorm: formatted as list(hvc = x) Where m is a single representative Munsell chip, thresh is a threshold specified in CIE2000 color contrast (dE00), hues is a vector of allowed Munsell hues, and x is a data.frame representing columns of Munsell hue, value, and chroma having at least 3 rows.
SPC	SoilProfileCollection, attempt to modify SPC with simulated colors

Value

a list, unless SPC is specified, then a SoilProfileCollection object

Author(s)

D.E. Beaudette

Examples

# restrict examples to 2 cores
data.table::setDTthreads(Sys.getenv("OMP_THREAD_LIMIT", unset = 2))

# m: representative or most likely color
# thresh: dE00 threshold
# hues: allowed Munsell hues
p <- list(
  'A' = list(m = '7.5YR 3/3', thresh = 5, hues = c('7.5YR')),
  'BA' = list(m = '7.5YR 4/4', thresh = 8, hues = c('7.5YR')),
  'Bt1' = list(m = '7.5YR 4/4', thresh = 8, hues = c('5YR', '7.5YR')),
  'Bt2' = list(m = '5YR 4/5', thresh = 8, hues = c('5YR', '7.5YR')),
  'Bt3' = list(m = '10YR 4/6', thresh = 10, hues = c('10YR', '7.5YR')),
  'Cr' = list(m = '2.5G 6/2', thresh = 15, hues = c('2.5G', '2.5GY', '2.5BG'))
)

# simulate
(cols <- simulateColor(method = 'dE00', n = 10, parameters = p))

# preview
previewColors(parseMunsell(unlist(cols)), method = 'MDS')

# another example, this time using a larger dE00 threshold
p <- list(
  'A' = list(m = '7.5YR 3/3', thresh = 20, hues = c('10YR', '7.5YR', '5YR'))
)

# simulate
set.seed(54654)
cols <- simulateColor(method = 'dE00', n = 200, parameters = p)

# flatten
cols <- unlist(cols)

# tabulate, sort: most frequent color should be 7.5YR 3/3
sort(table(cols), decreasing = TRUE)

# review colors
previewColors(parseMunsell(cols))

# what does a dE00 threshold look like on 3 pages of hue?
contrastChart('7.5YR 3/3', hues = c('10YR', '7.5YR', '5YR'), thresh = 20)

ncss-tech/aqp documentation built on April 19, 2024, 5:38 p.m.