zshift: Offset Raster or Matrix Values

In geodiv: Methods for Calculating Gradient Surface Metrics

Offset Raster or Matrix Values

Description

Calculates a matrix of values with a negative or positive, x or y, offset.

Usage

zshift(r, xdist = 0, ydist = 0, xrm, yrm, scale = FALSE)

Arguments

r	A raster or matrix.
xdist	Numeric indicating the number and direction (+, -) of columns for the offset.
ydist	Numeric indicating the number and direction (+, -) of rows for the offset.
xrm	Numeric value or vector indicating the number of columns to be removed from the final matrix. If not set, this value defaults to xdist. Positive values remove columns from the right, while negative values remove columns from the left. The absolute value of xrm must be >= abs(xdist).
yrm	Numeric value or vector indicating the number of rows to be removed from the final matrix. If not set, this value defaults to ydist. Positive values remove rows from the bottom, while negative values remove rows from the top. The absolute value must be >= abs(ydist).
scale	Logical. Indicates whether or not to scale the values of the raster.

Value

A numeric vector of values created from a matrix of the values with the specified offset. The vector is created from a matrix with xrm fewer columns and yrm fewer rows than the original raster value matrix.

Examples

# import raster image
data(normforest)
normforest <- terra::unwrap(normforest)

# remove right and bottom borders 2 deep
noborder <- zshift(normforest, xdist = 2, ydist = 2)

geodiv documentation built on Oct. 6, 2023, 1:07 a.m.