aqp (version 1.18)

get.increase.matrix: compute pair-wise distances to determine where an attribute increases within a vertical distance specified

Description

Uses matrix outer product to determine all pair-wise differences in `attr` for the horizons of `p`. Supplies `attr` to `threshold.fun` to determine the minimum value criterion to return TRUE in output matrix for an "increase". Also, computes all pair-wise distances in depth dimension to determine whether the vertical distance criteria have been met simultaneously with `attr` increase.

This function assumes that the `threshold.fun` supplied by the user returns either a constant or a vector of equal length to its input.

Note that the `threshold.fun` result is allowed to contain NA, but that will result in no output for affected cells.

get.increase.depths performs the conversion of the square matrix output of get.increase.matrix back to horizon top depth for where criteria were met.

Usage

get.increase.matrix(p, attr, threshold.fun, vertical.distance)

Arguments

p

a SoilProfileCollection, containing a single profile

attr

horizon attribute name to get the "increase" of

threshold.fun

a function that returns the threshold (as a function of attr); may return a constant single value

vertical.distance

the vertical distance (determined from difference SPC top depth variable) within which increase must be met

Value

Returns a square logical matrix reflecting where the increase criteria were met.

get.increase.depths converts to horizon dop depth by using above matrix output to determine depths where increase is met.

See Also

getArgillicBounds, crit.clay.argillic

Examples

# NOT RUN {
data(sp1, package = 'aqp')
depths(sp1) <- id ~ top + bottom
site(sp1) <- ~ group

p <- sp1[1]
attr <- 'prop' # clay contents 
foo <- get.increase.matrix(p, threshold.fun = crit.clay.argillic,
                           attr = attr, vertical.distance = 30)
foo
# }