hasDarkColors: Find horizons with colors darker than a Munsell hue, value,...

In aqp: Algorithms for Quantitative Pedology

Find horizons with colors darker than a Munsell hue, value, chroma threshold

Description

hasDarkColors returns a boolean value by horizon representing whether darkness thresholds are met. The code is fully vectorized and deals with missing data and optional thresholds.

Default arguments are set up for "5-3-3 colors" – the basic criteria for Mollic/Umbric epipedon/mineral soil darkness. Any of the thresholds or column names can be altered. Any thresholds that are set equal to NA will be ignored.

Usage

hasDarkColors(
  p,
  d_hue = NA,
  m_hue = NA,
  d_value = 5,
  d_chroma = NA,
  m_value = 3,
  m_chroma = 3,
  dhuenm = "d_hue",
  dvalnm = "d_value",
  dchrnm = "d_chroma",
  mhuenm = "m_hue",
  mvalnm = "m_value",
  mchrnm = "m_chroma"
)

Arguments

p	A SoilProfileCollection.
d_hue	Optional: character vector of dry hues to match (default: NA)
m_hue	Optional: character vector of moist hues to match (default: NA)
d_value	Maximum value of dry value (default: 5)
d_chroma	Optional: Maximum value of dry chroma (default: NA)
m_value	Maximum value of moist value (default: 3)
m_chroma	Maximum value of moist chroma (default: 3)
dhuenm	Column name containing dry hue.
dvalnm	Column name containing dry value.
dchrnm	Column name containing dry chroma.
mhuenm	Column name containing moist hue.
mvalnm	Column name containing moist value.
mchrnm	Column name containing moist chroma.

Value

Boolean value (for each horizon in p) reflecting whether "darkness" criteria are met.

Author(s)

Andrew G. Brown

Examples

# construct a fake profile
spc <- data.frame(id=1, taxsubgrp = "Lithic Haploxeralfs",
                  hzdesgn  = c("A","AB","Bt","BCt","R"),
                  hzdept   = c(0, 20, 32, 42,  49),
                  hzdepb   = c(20, 32, 42, 49, 200),
                  d_value  = c(5,   5,  5,  6,  NA),
                  m_value  = c(2.5, 3,  3,  4,  NA),
                  m_chroma = c(2,   3,  4,  4,  NA))

# promote to SoilProfileCollection
depths(spc) <- id ~ hzdept + hzdepb

# print results in table
data.frame(id = spc[[idname(spc)]],
           hz_desgn = spc$hzdesgn,
           has_dark_colors = hasDarkColors(spc))

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