Returns a 2x3 affine transformation matrix for rotating by angle
degrees counter-clockwise around (cx, cy) (1-based pixel
coordinates). To compose with other transforms, embed into a 3x3 matrix
with rbind(m, c(0, 0, 1)) before multiplying with %*%.
Usage
affine_rotate(angle, cx, cy, scale = 1)
Arguments
- angle
Numeric. Rotation angle in degrees, counter-clockwise.
- cx
Numeric. X coordinate of the rotation centre (1-based).
- cy
Numeric. Y coordinate of the rotation centre (1-based).
- scale
Numeric. Isotropic scale factor applied during rotation.
Default 1.
Value
A 2x3 numeric matrix.