mindspore.ops.svd

mindspore.ops.svd(input, full_matrices=False, compute_uv=True)

Computes the singular value decompositions of one or more matrices.

If $A$ is a matrix, the svd returns the singular values $S$, the left singular vectors $U$ and the right singular vectors $V$. It meets:

$$A=U\ast diag(S)\ast V^T$$

Parameters

• input (Tensor) – Tensor of the matrices to be decomposed. The shape should be $(\ast ,M,N)$, the supported dtype are float32 and float64.

• full_matrices (bool, optional) – If true, compute full-sized $U$ and $V$. If false, compute only the leading P singular vectors, with P is the minimum of M and N. Default: False .

• compute_uv (bool, optional) – If true, compute the left and right singular vectors. If false, compute only the singular values. Default: True .

Returns

• s (Tensor) - Singular values. The shape is $(\ast ,P)$.

• u (Tensor) - Left singular vectors. If compute_uv is False, u will not be returned. The shape is $(\ast ,M,P)$. If full_matrices is True, the shape will be $(\ast ,M,M)$.

• v (Tensor) - Right singular vectors. If compute_uv is False, v will not be returned. The shape is $(\ast ,N,P)$. If full_matrices is True, the shape will be $(\ast ,N,N)$.

Raises

• TypeError – If full_matrices or compute_uv is not the type of bool.

• TypeError – If the rank of input less than 2.

• TypeError – If the type of input is not one of the following dtype: float32, float64.

Supported Platforms:

GPU CPU

Examples

>>> import numpy as np
>>> from mindspore import Tensor, set_context
>>> from mindspore import ops
>>> set_context(device_target="CPU")
>>> input = Tensor(np.array([[1, 2], [-4, -5], [2, 1]]).astype(np.float32))
>>> s, u, v = ops.svd(input, full_matrices=True, compute_uv=True)
>>> print(s)
[7.0652843 1.040081 ]
>>> print(u)
[[ 0.30821905 -0.48819482 0.81649697]
 [-0.90613353  0.11070572 0.40824813]
 [ 0.2896955   0.8656849  0.4082479 ]]
>>> print(v)
[[ 0.63863593 0.769509  ]
 [ 0.769509  -0.63863593]]