Fix empty dimensions (#60)

* only squeeze singular dimensions if array is 2D

* increment version

mat73/core.py

@@ -305,25 +305,14 @@ def convert_mat(self, dataset, depth, MATLAB_class=None):
 
 
 def squeeze(arr):
-    # Assumption: "superfluous" singular dimensions come at the beginning or the end
-
-    shape = arr.shape
-    if len(shape) == 0:
-        return arr
-
-    # Remove leading dimensions of size 1
-    while len(shape) > 1 and shape[0] == 1:
-        shape = shape[1:]
-
-    # Remove trailing dimensions of size 1
-    while len(shape) > 1 and shape[-1] == 1:
-        shape = shape[:-1]
-
-    # If all remaining dimensions are of size 1, reduce to 0-dimensional
-    if len(shape) == 1 and shape[0] == 1:
-        shape = ()
-
-    return arr.reshape(shape)
+    """Vectors are saved as 2D matrices in MATLAB, however in numpy
+    there is no distinction between a column and a row vector. 
+    Therefore, remove superfluous dimensions if the array is 2D and
+    one of the dimensions is singular"""
+    if arr.ndim==2 and 1 in arr.shape:
+        return arr.reshape([x for x in arr.shape if x>1])
+    return arr
+
 
 def loadmat(file, use_attrdict=False, only_include=None, verbose=True):
     """

mat73/version.py

@@ -1 +1 @@
-__version__ = '0.64'
+__version__ = '0.65'

tests/create_mat.m

@@ -46,4 +46,22 @@
 A = sparse([0 0 0; 0 0 0]);
 save('testfile13.mat','-v7.3')
 clear all
-%% 
+%% third file: create a file to test all kind of empty dimensions that migh pop up
+
+x_0 = rand(0)
+x_1 = rand(1)
+x_10 = 1:10
+x_1_0 = rand(1, 0)
+x_0_1 = rand(0, 1)
+x_1_1 = rand(1, 1)
+x_0_10 = rand(0, 10)
+x_1_10 = rand(1, 10)
+x_10_0 = rand(10, 0)
+x_10_1 = rand(10, 1)
+x_10_10 = rand(10, 10)
+x_1_1_10_1_1 = rand(1, 1, 10, 1, 1)
+x_10_1_1_10 = rand(10, 1, 1, 10)
+save('testfile15.mat','-v7.3')
+clear all
+
+

tests/test_mat73.py

@@ -15,6 +15,7 @@
     version = pkg_resources.get_distribution('mat73').version
 except:
     version = '0.00'
+
 try:
     repo = Repository('.')
     head = repo.head
@@ -34,7 +35,7 @@ class Testing(unittest.TestCase):
 
     def setUp(self):
         """make links to test files and make sure they are present"""
-        for i in range(1, 15):
+        for i in range(1, 16):
             file = 'testfile{}.mat'.format(i)
             if not os.path.exists(file):
                 file = os.path.join('./tests', file)
@@ -476,6 +477,39 @@ def test_file14_n_d_array_with_singular_axis(self):
         # Test that the singular dimension is preserved
         self.assertEqual(arr.shape[1], 1)
 
+
+
+    def test_file15_strip(self):
+        """Test loading of n-D array with one dimension of size 1"""
+
+        # the array was created in Matlab like so:
+        # data = reshape(1:24, [3, 1, 4, 2]);
+
+        data = mat73.loadmat(self.testfile15)
+
+
+        self.assertEqual(data['x_0'], None)
+        self.assertEqual(data['x_1_0'], None)
+        self.assertEqual(data['x_0_1'], None)
+        self.assertEqual(data['x_0_10'], None)
+        self.assertEqual(data['x_10_0'], None)
+
+        expected = {'x_1' : (),
+                    'x_10' : (10,),
+                    'x_1_1': (),
+                    'x_1_10': (10,),
+                    'x_10_1': (10,),
+                    'x_10_10': (10, 10),
+                    'x_1_1_10_1_1': (1, 1, 10),
+                    'x_10_1_1_10': (10, 1, 1, 10),
+                    }
+
+
+        for var, shape in expected.items():
+            self.assertEqual(data[var].shape, shape)
+            self.assertEqual(data[var].ndim, len(shape))
+
+
 if __name__ == '__main__':
 
     unittest.main()