Skip to content

Class ParamKoopman

It represents a mapping \(K: \mathrm{span}(\Psi) \times U \rightarrow \mathrm{span}(\Psi)\), which is a finite-dimensional approximation of the parametric Koopman operator.

API Documentation

size property

Returns the size of the Koopman matrix.

Returns:

Type Description
int

The row/column size of the Koopman matrix.

__call__(x, u)

Applies the Koopman operator to the input tensor x using the parameter tensor u.

Parameters:

Name Type Description Default
x Tensor

The input tensor of shape \((N, N_\psi)\).

required
u Tensor

The parameter tensor of shape \((1, N_u)\) or \((N, N_u)\). If u has a size of 1 in the first dimension, it will be expanded to match the batch size of x.

required

Returns:

Type Description
Tensor

The result of applying the Koopman operator, with the same batch size as x and the transformed dimension.

__init__(size_K, network)

Initialize the ParamKoopman instance.

Parameters:

Name Type Description Default
size_K int

The size of the Koopman matrix.

required
network Module

The network to generate the Koopman operator.

required

eval()

Sets the network to evaluation mode.

load(path)

Loads the model state and size from a specified file path.

Parameters:

Name Type Description Default
path str

The file path from which to load the model data.

required

parameters()

Retrieve the parameters of the network.

Returns:

Type Description
Iterator[Parameter]

An iterator over the parameters of the network.

save(path)

Saves the current state of the network to a file.

Parameters:

Name Type Description Default
path str

The file path where the state dictionary and size will be saved.

required

step(x, u)

Computes the next step in the system given the current state and parameter.

Parameters:

Name Type Description Default
x Tensor

The current state of the system.

required
u Tensor

The control input to the system.

required

Returns:

Type Description
Tensor

The next state of the system after applying the Koopman.

train()

Sets the network to training mode.