# Copyright 2014, Sandia Corporation. Under the terms of Contract
# DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain
# rights in this software.
"""Functions for manipulating transformation matrices."""
import numpy
[docs]def rotation(angle):
"""Return a 2D transformation matrix.
Parameters
----------
angle: number
Rotation angle in degrees. Positive values produce counterclockwise rotation.
"""
theta = numpy.radians(angle)
cos_theta = numpy.cos(theta)
sin_theta = numpy.sin(theta)
return numpy.array([[cos_theta, sin_theta], [-sin_theta, cos_theta]])