Loading a .mat reconstruction

RawMRISeries (and everything built on it — MRSSeries, MRSISeries, MRSWashinSeries) reads its recon dict from load_mat_file under the hood. Scanner reconstructions come in two MATLAB file formats depending on size and MATLAB version — plain (v5/v7, scipy-readable) and v7.3 (HDF5-based, needs mat73) — and load_mat_file hides that distinction behind one call.

from loguru import logger

logger.remove()

from mnutils.utils import data_loaders as dl
from mnutils.utils import file_helpers as fh
from mnutils.testing import build_fake_exam

mrsi_missing_series_exam = build_fake_exam("mrsi_missing_series_exam")

The current format¶

mat_path = fh.get_mat_data_from_series(mrsi_missing_series_exam, 7)
data = dl.load_mat_file(mat_path)
print(type(data), sorted(data.keys())[:5])
print(data["spec"].shape)

<class 'dict'> ['__globals__', '__header__', '__version__', 'bb', 'h']
(700, 16, 16, 16)

# STRICT TESTS: current-format .mat
assert isinstance(data, dict)
assert "bb" in data
assert data["spec"].shape[0] == 700

The older (v7.3) format¶

Older reconstructions saved as MATLAB v7.3 fail the plain scipy.io.loadmat path and fall back to mat73 transparently — same call, same return type.

legacy_data = dl.load_mat_file(build_fake_exam("legacy_matlab73_example"))
print("pyr" in legacy_data)

True

# STRICT TESTS: legacy-format .mat
assert isinstance(legacy_data, dict)
assert "pyr" in legacy_data

When the path isn’t a real .mat file¶

import pytest

with pytest.raises(FileNotFoundError):
    dl.load_mat_file("/nonexistent/file.mat")