scipy.linalg.tanm

scipy.linalg.tanm(A)

Compute the matrix tangent.

This routine uses expm to compute the matrix exponentials.

Parameters:

A : (N, N) array_like

Input array.

Returns:

tanm : (N, N) ndarray

Matrix tangent of A

Examples

>>> from scipy.linalg import tanm, sinm, cosm
>>> a = np.array([[1.0, 3.0], [1.0, 4.0]])
>>> t = tanm(a)
>>> t
array([[ -2.00876993,  -8.41880636],
       [ -2.80626879, -10.42757629]])

Verify tanm(a) = sinm(a).dot(inv(cosm(a)))

>>> s = sinm(a)
>>> c = cosm(a)
>>> s.dot(np.linalg.inv(c))
array([[ -2.00876993,  -8.41880636],
       [ -2.80626879, -10.42757629]])