hzOffset: Horizons Above or Below

In aqp: Algorithms for Quantitative Pedology

Horizons Above or Below

Description

Horizons Above or Below

Usage

hzAbove(x, ..., offset = 1, SPC = TRUE, simplify = SPC)

hzBelow(x, ..., offset = 1, SPC = TRUE, simplify = SPC)

hzOffset(x, hzid, offset, SPC = FALSE, simplify = TRUE)

Arguments

x	A SoilProfileCollection
...	Comma-separated set of R expressions that evaluate as TRUE or FALSE in context of horizon data frame. Length for individual expressions matches number of horizons, in x.
offset	Integer offset in terms of SoilProfileCollection ⁠[,j]⁠ (horizon/slice) index
SPC	Return a SoilProfileCollection? Default TRUE for ⁠horizon_*⁠ methods.
simplify	If TRUE return a vector (all elements combined), or a list (1 element per profile). If SPC is TRUE then simplify is TRUE.
hzid	A vector of target horizon IDs. These are calculated from ... for ⁠horizon_*()⁠ methods

Details

To minimize likelihood of issues with non-standard evaluation context, especially when using hzAbove()/hzBelow() inside another function, all expressions used in ... should be in terms of variables that are in the horizon data frame.

Value

A SoilProfileCollection (when SPC = TRUE) or a vector of horizon row indices (when SPC = FALSE and simplify = TRUE) or a list (when SPC = FALSE and simplify = FALSE))

Examples

data(sp4)
depths(sp4) <- id ~ top + bottom

# get the horizon above the last horizon (j-index of bottom horizon minus 1)
hzAbove(sp4, hzID(sp4) %in% getLastHorizonID(sp4))

# get horizons below the last horizon (none; j-index of bottom horizon plus 1)
hzBelow(sp4, hzID(sp4) %in% getLastHorizonID(sp4))

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