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read_mat

ReadMat

Bases: NumpyOp

A class for reading .mat files from disk.

This expects every sample to have a separate .mat file.

Parameters:

Name Type Description Default
inputs str

Dictionary key that contains the .mat path.

 required
outputs Union[str, Iterable[str]]

Keys to output from the mat file.

 required
mat_keys Union[None, str, Iterable[str]]

(Optional) Keys to read from the .mat file. Defaults to outputs, but to re-name keys you can provide the original name here and the new name in outputs.

 None
mode Union[None, str, Iterable[str]]

What mode(s) to execute this Op in. For example, "train", "eval", "test", or "infer". To execute regardless of mode, pass None. To execute in all modes except for a particular one, you can pass an argument like "!infer" or "!train".

 None
ds_id Union[None, str, Iterable[str]]

What dataset id(s) to execute this Op in. To execute regardless of ds_id, pass None. To execute in all ds_ids except for a particular one, you can pass an argument like "!ds1".

 None
parent_path str

Parent path that will be prepended to a given filepath.

 ''
Source code in fastestimator/fastestimator/op/numpyop/multivariate/read_mat.py 
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@traceable()
class ReadMat(NumpyOp):
    """A class for reading .mat files from disk.

    This expects every sample to have a separate .mat file.

    Args:
        inputs: Dictionary key that contains the .mat path.
        outputs: Keys to output from the mat file.
        mat_keys: (Optional) Keys to read from the .mat file. Defaults to `outputs`, but to re-name keys you can provide
            the original name here and the new name in `outputs`.
        mode: What mode(s) to execute this Op in. For example, "train", "eval", "test", or "infer". To execute
            regardless of mode, pass None. To execute in all modes except for a particular one, you can pass an argument
            like "!infer" or "!train".
        ds_id: What dataset id(s) to execute this Op in. To execute regardless of ds_id, pass None. To execute in all
            ds_ids except for a particular one, you can pass an argument like "!ds1".
        parent_path: Parent path that will be prepended to a given filepath.
    """
    def __init__(self,
                 inputs: str,
                 outputs: Union[str, Iterable[str]],
                 mat_keys: Union[None, str, Iterable[str]] = None,
                 mode: Union[None, str, Iterable[str]] = None,
                 ds_id: Union[None, str, Iterable[str]] = None,
                 parent_path: str = ""):
        super().__init__(inputs=inputs, outputs=outputs, mode=mode, ds_id=ds_id)
        self.parent_path = parent_path

        if mat_keys is None:
            self.mat_keys = self.outputs
        else:
            self.mat_keys = to_list(mat_keys)

        self.out_list = True

        if isinstance(self.mat_keys, List) and isinstance(self.outputs, List):
            assert len(self.mat_keys) == len(self.outputs), "keys and Output lengths must match"

    def forward(self, data: str, state: Dict[str, Any]) -> List[Dict[str, Any]]:
        input_path = os.path.normpath(os.path.join(self.parent_path, data))
        data = loadmat(input_path)
        results = [data[key] for key in self.mat_keys]
        return results