Fixed expand dims bug

pytorch_wavelets/dtcwt/lowlevel.py

@@ -59,8 +59,7 @@ def prep_filt(h, c, transpose=False):
     """ Prepares an array to be of the correct format for pytorch.
     Can also specify whether to make it a row filter (set tranpose=True)"""
     h = _as_col_vector(h)[::-1]
-    #h = np.reshape(h, [1, 1, *h.shape])
-    h = np.expand_dims(h, (0,1))
+    h = h[None, None, :]
     h = np.repeat(h, repeats=c, axis=0)
     if transpose:
         h = h.transpose((0,1,3,2))