| hasDarkColors {aqp} | R Documentation | 
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))