Added a check and modified tests for 1D mpi-ffts to deal with issues in FFTW:

https://github.com/fredRos/pyFFTW/issues/8
https://github.com/fredRos/pyFFTW/issues/9

nifty/operators/fft_operator/transformations/rg_transforms.py

@@ -373,6 +373,10 @@ class MPIFFT(Transform):
                 original_shape = inp.shape
                 inp = inp.reshape(inp.shape[0], 1)
                 axes = (0, )
+                if original_shape[0]%2!=0:
+                    raise AttributeError("MPI-FFTs of onedimensional arrays "
+                        "with odd length are currently not supported due to a "
+                        "bug in FFTW. Please use a grid with even length.")
 
             if current_info is None:
                 transform_shape = list(inp.shape)

test/test_operators/test_fft_operator.py

@@ -63,7 +63,7 @@ class FFTOperatorTests(unittest.TestCase):
         assert_equal(res[zc1 * (dim1 // 2), zc2 * (dim2 // 2)], 0.)
 
     @expand(product(["numpy", "fftw", "fftw_mpi"],
-                    [10, 11], [False, True], [False, True],
+                    [12, ], [False, True], [False, True],
                     [0.1, 1, 3.7],
                     [np.float64, np.complex128, np.float32, np.complex64]))
     def test_fft1D(self, module, dim1, zc1, zc2, d, itp):
@@ -86,7 +86,7 @@ class FFTOperatorTests(unittest.TestCase):
                         rtol=tol, atol=tol)
 
     @expand(product(["numpy", "fftw", "fftw_mpi"],
-                    [10, 11], [9, 12], [False, True],
+                    [12, 15], [9, 12], [False, True],
                     [False, True], [False, True], [False, True], [0.1, 1, 3.7],
                     [0.4, 1, 2.7],
                     [np.float64, np.complex128, np.float32, np.complex64]))

test/test_serialization.py

@@ -39,4 +39,7 @@ class SpaceSerializationTests(unittest.TestCase):
         repo.commit()
         assert_equal(space, repo.get('space'))
         assert_equal(field, repo.get('field'))
+        try:
             os.remove('test.h5')
+        except OSError:
+            pass