''Recycling Krylov subspaces for sequences of linear systems'',
       SIAM J. Sci. Comput. 28, 1651 (2006).

Examples
--------
>>> import numpy as np
>>> from scipy.sparse import csc_array
>>> from scipy.sparse.linalg import gcrotmk
>>> R = np.random.randn(5, 5)
>>> A = csc_array(R)
>>> b = np.random.randn(5)
>>> x, exit_code = gcrotmk(A, b, atol=1e-5)
>>> print(exit_code)
0
>>> np.allclose(A.dot(x), b)
True

z$RHS must contain only finite numbers)