Source code for openmdao.utils.cs_safe

"""
collection of complex-step safe functions to replace standard numpy operations.
"""

import numpy as np


[docs]def abs(x): """ complex-step safe version of numpy.abs function. Parameters ---------- x : ndarray array value to be computed on Returns ------- ndarray """ if isinstance(x, np.ndarray): return x * np.sign(x) elif x.real < 0.0: return -x return x
[docs]def norm(x, axis=None): """ complex-step safe version of numpy.linalg.norm function. Parameters ---------- x : ndarray array value to be computed on axis : None or int axis to perform the norm up to Returns ------- ndarray """ return np.sqrt(np.sum(x**2, axis=axis))
[docs]def arctan2(y, x): """ Numpy-compatible, complex-compatible arctan2 function for use with complex-step. Parameters ---------- y : float or complex The length of the side opposite the angle being determined. x : float or complex The length of the side adjacent to the angle being determined. Returns ------- ndarray The angle whose opposite side has length y and whose adjacent side has length x. """ if np.iscomplexobj(x) or np.iscomplexobj(y): a = np.real(y) b = np.imag(y) c = np.real(x) d = np.imag(x) return np.arctan2(a, c) + 1j * (c * b - a * d) / (a**2 + c**2) else: return np.arctan2(y, x)