Function _check_preload

mne/utils/check.py:331–351

Ensure data are preloaded.

(inst, msg)

def _check_preload(inst, msg):
    """Ensure data are preloaded."""
    from ..epochs import BaseEpochs
    from ..evoked import Evoked
    from ..source_estimate import _BaseSourceEstimate
    from ..time_frequency import BaseTFR
    from ..time_frequency.spectrum import BaseSpectrum

    if isinstance(inst, BaseTFR | Evoked | BaseSpectrum | _BaseSourceEstimate):
        pass
    else:
        name = "epochs" if isinstance(inst, BaseEpochs) else "raw"
        if not inst.preload:
            raise RuntimeError(
                "By default, MNE does not load data into main memory to "
                "conserve resources. " + msg + f" requires {name} data to be "
                "loaded. Use preload=True (or string) in the constructor or "
                f"{name}.load_data()."
            )
        if name == "epochs":
            inst._handle_empty("raise", msg)


def _check_compensation_grade(info1, info2, name1, name2="data", ch_names=None):