numpy.matrix.var

method

matrix.var(axis=None, dtype=None, out=None, ddof=0)[源代码]

Returns the variance of the matrix elements, along the given axis.

Refer to numpy.var for full documentation.

参见

numpy.var

Notes

This is the same as ndarray.var, except that where an ndarray would be returned, a matrix object is returned instead.

Examples

>>> x = np.matrix(np.arange(12).reshape((3, 4)))
>>> x
matrix([[ 0,  1,  2,  3],
        [ 4,  5,  6,  7],
        [ 8,  9, 10, 11]])
>>> x.var()
11.916666666666666
>>> x.var(0)
matrix([[ 10.66666667,  10.66666667,  10.66666667,  10.66666667]])
>>> x.var(1)
matrix([[ 1.25],
        [ 1.25],
        [ 1.25]])