warpHorizons: Inflate / Deflate Horizon Thickness

In aqp: Algorithms for Quantitative Pedology

Inflate / Deflate Horizon Thickness

Description

This function applies a warping factor to the horizons of a single-profile SoilProfileCollection object. Warping values >1 will inflate horizon thickness, values <1 will deflate horizon thickness.

Usage

warpHorizons(x, fact, updateProfileID = TRUE, suffix = "-w")

Arguments

x	a SoilProfileCollection object
fact	numeric or character; warping factor specified as a single numeric value, vector of numeric values (length = nrow(x)), or column name of a horizon level attribute containing numeric values
updateProfileID	logical; modify profile IDs
suffix	character; suffix added to profile IDs when updateProfileID = TRUE

Value

a modified version of x, SoilProfileCollection object

Author(s)

D.E. Beaudette and S.W. Salley

Examples

# create an example profile
s <- quickSPC('p1:AA|Bt1Bt1Bt1|Bt2Bt2B|Bt3|Cr|RRRRR')

# warp each horizon
# values > 1: inflation
# values < 1: deflation (erosion / compaction)
s.w <- warpHorizons(s, fact = c(1.3, 0.7, 0.8, 1, 1, 1))

# combine original + warped
x <- combine(s, s.w)

# compute profile bottom depths
.bottoms <- x[, , .LAST, .BOTTOM]

# change in total depth after warping
# used to vertically offset the warped profile
.yoff <- c(0, .bottoms[1] - .bottoms[2])

# depths for line segments connecting horizon tops
.y1 <- x[1, , .TOP]
.y2 <- x[2, , .TOP] + .yoff[2]

# sketches
# can't automatically add a depth axis
par(mar = c(0.5, 0, 0, 2))
plotSPC(
  x, 
  name.style = 'center-center', 
  cex.names = 0.8, 
  width = 0.2, 
  max.depth = 150, 
  depth.axis = list(line = -3), 
  y.offset = .yoff
)

# illustrate warping with arrows
arrows(x0 = 1 + 0.25, y0 = .y1, x1 = 2 - 0.25, y1 = .y2, len = 0.1, col = 2)

# manually add depth axis
axis(side = 4, line = -3.5, las = 1, at = seq(from = 0, to = 150, by = 25))


# apply to multiple profiles
# text-based template
.template <- c(
'P1:AAA|BwBwBwBw|CCCCCCC|CdCdCdCd',
'P2:ApAp|AA|E|BhsBhs|Bw1Bw1|CCCCC',
'P3: A|Bt1Bt1Bt1|Bt2Bt2Bt2|Bt3|Cr|RRRRR'
)

# each horizon label is '10' depth-units (default)
s <- quickSPC(.template)

# random warping factor, by horizon
s$f <- runif(n = nrow(s), min = 0.8, max = 1.2)

# warp horizons by profile, result is a list of SPCs
s.w <- profileApply(s, FUN = warpHorizons, fact = 'f')

# flatten list -> SoilProfileCollection
s.w <- combine(s.w)

# combine with original SPC
x <- combine(s, s.w)

# sketches 
par(mar = c(0.5, 0, 0, 2.5))
plotSPC(
  x,
  name.style = 'center-center',
  cex.names = 0.8,
  width = 0.3,
  max.depth = 165,
  depth.axis = list(line = -2)
)

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