def inv(x):
if sps.issparse(x): return <NUM_LIT:1.0> / x.toarray()        <EOL>else:               return <NUM_LIT:1.0> / np.asarray(x)<EOL>
inv(x) yields the inverse of x, 1/x.

Note that inv supports sparse matrices, but it is forced to reify them. Additionally, because
inv raises an error on divide-by-zero, they are unlikely to work. For better sparse-matrix
support, see zinv.