'Return the minimum of the matrix or maximum along an axis.
This takes all elements into account, not just the non-zero ones.
Parameters
axis : {-2, -1, 0, 1, None} optional
Axis along which the sum is computed. The default is to
compute the minimum over all the matrix elements, returning
a scalar (i.e. `axis` = `None`).
out : None, optional
This argument is in the signature *solely* for NumPy
compatibility reasons. Do not pass in anything except for
the default value, as this argument is not used.
Returns
amin : coo_matrix or scalar
Minimum of `a`. If `axis` is None, the result is a scalar value.
If `axis` is given, the result is a sparse.coo_matrix of dimension
``a.ndim - 1``.
See Also
max : The maximum value of a sparse matrix along a given axis.
np.matrix.min : NumPy\'s implementation of \'min\' for matrices'

def min(self, axis=None, out=None):

    return self._min_or_max(axis, out, np.minimum)
