annulus.matrix: Annulus matrix

In jeffreyevans/spatialEco: Spatial Analysis and Modelling Utilities

Annulus matrix

Description

Creates a square matrix representing annulus position values of 1 and defined null

Usage

annulus.matrix(scale = 3, inner.scale = 0, outer.scale = 0, null.value = 0)

Arguments

scale	Number of rings (defines dimensions of matrix)
inner.scale	Number of inner rings to set to null.value
outer.scale	Number of outer rings to set to null.value
null.value	Value to set inner and outer scale(s) to

Details

This function will return a matrix of 1 and defined null.value based on a specification of the scale, inner scale and outer scale. The scale defines how many rings will be represented in the matrix based on (2 * scale - 1). So, a scale of 3 will result in a 5x5 matrix. The inner.scale and outer.scale arguments represent the > and < rings that will be set to the defined null.value (see examples). The resulting matrix can be used as the specified window in a focal function.

Value

A matrix object with defined null.value and 1, representing retained rings

Author(s)

Jeffrey S. Evans <[e-mail]>

Examples

annulus.matrix(5)                   # 5 concentric rings
annulus.matrix(5, 3)                # 5 concentric rings with the 3 inner set to 0
annulus.matrix(5, 3, null.value=NA) # 5 concentric rings with the 3 inner set to NA
annulus.matrix(5, 3, 5)             # 5 rings with 3 inner and 5 outer set to 0
annulus.matrix(9, 3, 7)             # 9 rings with 3 inner and 7 outer set to 0

jeffreyevans/spatialEco documentation built on April 4, 2024, 10:53 a.m.