visualdynamics.io.rattlesnake_state_space

rattlesnake_state_space

Write a modal state-space model as Rattlesnake's state-space hardware file.

The controller's state-space virtual hardware loads a NumPy .npz (or MATLAB .mat) holding A, B, C and D, integrates the model at its sample rate, and returns C x + D u as each channel's value. It checks that C and D have a row per channel of its channel table and that B and D have a column per channel with a feedback device, the drives, so the model is written for one table and matches that table row for row (core.state_space).

The file also holds channel_dof, input_dof, channel_unit and mode_frequency, which the controller ignores. They say what the rows, the columns and the states are, since the file has no other place for units.

Functions:

Name	Description
save	Write model to path as an uncompressed .npz.

Classes

Functions:

save

save(model: StateSpaceModel, path: str | PathLike) -> None

Write model to path as an uncompressed .npz.

Parameters:

Name	Type	Description	Default
model	StateSpaceModel	The model to write.	required
path	str or PathLike	Where to write it.	required

Returns:

Type	Description
None

Source code in src/visualdynamics/io/rattlesnake_state_space.py

def save(model: StateSpaceModel, path: str | os.PathLike) -> None:
    """Write `model` to `path` as an uncompressed `.npz`.

    Parameters
    ----------
    model : StateSpaceModel
        The model to write.
    path : str or os.PathLike
        Where to write it.

    Returns
    -------
    None
    """
    np.savez(path, A=model.A, B=model.B, C=model.C, D=model.D,
             channel_dof=np.array(model.channel_dof, dtype=str),
             input_dof=np.array(model.input_dof, dtype=str),
             channel_unit=np.array(model.channel_unit, dtype=str),
             mode_frequency=np.asarray(model.mode_frequency, dtype=float))