decomposeAffine: Decompose an affine matrix into its constituent transformations
Description
An affine matrix is composed of translation, scale, skew and rotation
transformations. This function extracts these components, after first
inverting the matrix so that it transforms from source to target space.
Usage
decomposeAffine(affine)
Arguments
affine
A 4x4 matrix representing an affine transformation matrix.
Value
A list with components:
scaleMatrix
A 3x3 matrix representing only the scale operation
embodied in the full affine transformation.
skewMatrix
A 3x3 matrix representing only the skew operation
embodied in the full affine transformation.
rotationMatrix
A 3x3 matrix representing only the rotation
operation embodied in the full affine transformation.
translation
A length-3 named numeric vector representing the
translations (in pixunits units) in each of the X, Y and
Z directions.
scales
A length-3 named numeric vector representing the scale
factors in each of the X, Y and Z directions. Scale factors of 1
represent no effect.
skews
A length-3 named numeric vector representing the skews in
each of the XY, XZ and YZ planes.
angles
A length-3 named numeric vector representing the rotation
angles (in radians) about each of the X, Y and Z directions, i.e.,
roll, pitch and yaw.