# get.increase.matrix: Compute Pair-wise Distances of Soil Properties over Depth In aqp: Algorithms for Quantitative Pedology

 get.increase.matrix R Documentation

## Compute Pair-wise Distances of Soil Properties over Depth

### Description

Computes pair-wise distance matrix to determine where an attribute increases within a specified vertical distance threshold.

`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)

get.increase.depths(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

### Details

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.

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

### Value

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

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

Returns a numeric vector of depths where the increase requirement is met. For the argillic, the first is the one of interest.

`get.increase.depths()` converts to horizon top depth by using above matrix output to determine depths where increase is met.

### Author(s)

Andrew Gene Brown

`getArgillicBounds()`, `crit.clay.argillic()`

`getArgillicBounds()` `crit.clay.argillic()`

### Examples

``````
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

data(sp1, package = 'aqp')
depths(sp1) <- id ~ top + bottom
site(sp1) <- ~ group

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

``````

aqp documentation built on Sept. 11, 2024, 7:11 p.m.