rotateMatrix: Rotate values in a matrix

In adamlilith/omnibus: Helper Tools for Managing Data, Dates, Missing Values, and Text

Rotate values in a matrix

Description

This function rotates the values in a matrix by a user-specified number of degrees. In almost all cases some values will fall outside the matrix so they will be discarded. Cells that have no rotated values will become NA. Only square matrices can be accommodated. In some cases a rotation will cause cells to have no assigned value because no original values fall within them. In these instances the mean value of surrounding cells is assigned to the cells with missing values. If the angle of rotation is too small then no rotation will occur.

Usage

rotateMatrix(x, rot)

Arguments

x	A matrix.
rot	Numeric. Number of degrees to rotate matrix. Values represent difference in degrees between "north" (up) and the clockwise direction.

Value

A matrix.

See Also

[base::t()]

Examples

x <- matrix(1:100, nrow=10)
x
rotateMatrix(x, 90) # 90 degrees to the right
rotateMatrix(x, 180) # 180 degrees to the right
rotateMatrix(x, 45) # 45 degrees to the right
rotateMatrix(x, 7) # slight rotation
rotateMatrix(x, 5) # no rotation because angle is too small

adamlilith/omnibus documentation built on April 12, 2024, 8:46 p.m.