speed up _is_ref check

mat73/__init__.py

@@ -65,7 +65,6 @@ def mat2dict(self, hdf5, only_load=None):
                 raise ValueError('can only unpack .mat')
         return d
 
-
     def unpack_mat(self, hdf5, depth=0):
         """
         unpack a h5py entry: if it's a group expand,
@@ -115,15 +114,13 @@ def unpack_mat(self, hdf5, depth=0):
         else:
             raise Exception(f'Unknown hdf5 type: {key}:{type(hdf5)}')
 
-
+    # @profile
     def _has_refs(self, dataset):
-        if len(dataset)==0: return False
-        if not isinstance(dataset[0], np.ndarray): return False
+        if len(dataset.shape)<2: return False
         if isinstance(dataset[0][0], h5py.h5r.Reference):  
             return True
         return False
 
-
     def convert_mat(self, dataset, depth):
         """
         Converts h5py.dataset into python native datatypes
@@ -244,5 +241,5 @@ def savemat(filename, verbose=True):
     # d = loadmat('../tests/testfile5.mat', use_attrdict=True)
 
 
-    file = '../tests/testfile7.mat'
+    file = '../tests/testfile8.mat'
     data = loadmat(file)

setup.py

@@ -4,14 +4,14 @@
 
 setuptools.setup(
      name='mat73',  
-     version='0.52',
+     version='0.53',
      author="skjerns",
      author_email="[email protected]",
      description="Load MATLAB .mat 7.3 into Python native data types",
      long_description=long_description,
    long_description_content_type="text/markdown",
      url="https://github.com/skjerns/mat7.3",
-     download_url="https://github.com/skjerns/mat7.3/archive/v0.52.tar.gz",
+     download_url="https://github.com/skjerns/mat7.3/archive/v0.53.tar.gz",
      install_requires=['h5py', 'numpy'],
      license='MIT',
      packages=['mat73'],

tests/test_mat73.py

@@ -31,7 +31,7 @@
 class Testing(unittest.TestCase):
 
     def setUp(self):
-        for i in range(1,8):
+        for i in range(1,9):
             file = 'testfile{}.mat'.format(i)
             if not os.path.exists(file):
                 file = os.path.join('./tests', file)
@@ -337,7 +337,11 @@ def test_file6_empty_cell_array(self):
     def test_file7_empty_cell_array(self):
         data = mat73.loadmat(self.testfile7)
 
-
+    def test_file8_large(self):
+        import stimer
+        with stimer:
+            data = mat73.loadmat(self.testfile8)
+
 
 
 if __name__ == '__main__':