mindflow.operators.batched_hessian

mindflow.operators.batched_hessian(model)

Calculate Hessian matrix of network model.

Parameters

model (mindspore.nn.Cell) – a network with the input dimension is in_channels and output dimension is out_channels.

Returns

hessian(Tensor), hessian of the model. With the input dimension is [batch_size, in_channels], output dimension is [out_channels, in_channels, batch_size, in_channels].

Note

The version of MindSpore should be >= 2.0.0 for using mindspore.jacrev.

Supported Platforms:

Ascend GPU CPU

Examples

>>> import numpy as np
>>> from mindspore import nn, ops, Tensor
>>> from mindspore import dtype as mstype
>>> from mindflow.operators import batched_hessian
>>> np.random.seed(123456)
>>> class Net(nn.Cell):
...     def __init__(self, cin=2, cout=1, hidden=10):
...         super().__init__()
...         self.fc1 = nn.Dense(cin, hidden)
...         self.fc2 = nn.Dense(hidden, hidden)
...         self.fcout = nn.Dense(hidden, cout)
...         self.act = ops.Tanh()
...
...     def construct(self, x):
...         x = self.act(self.fc1(x))
...         x = self.act(self.fc2(x))
...         x = self.fcout(x)
...         return x
>>> model = Net()
>>> hessian = batched_hessian(model)
>>> inputs = np.random.random(size=(3, 2))
>>> res = hessian(Tensor(inputs, mstype.float32))
>>> print(res.shape)
(1, 2, 3, 2)