Merge pull request tensorly#591 from dontempty/maxvol-adjustment

Update _tt_cross.py

Author: JeanKossaifi

tensorly/contrib/decomposition/_tt_cross.py

@@ -452,18 +452,15 @@ def maxvol(A):
 
         # Find the row of max norm
         max_row_idx = tl.argmax(rows_norms, axis=0)
-        max_row = A[rest_of_rows[max_row_idx], :]
+        max_row = A_new[max_row_idx, :]
 
         # Compute the projection of max_row to other rows
-        # projection a to b is computed as: <a,b> / sqrt(|a|*|b|)
+        # projection = <b, a>/|a|^2
         projection = tl.dot(A_new, tl.transpose(max_row))
-        normalization = tl.sqrt(rows_norms[max_row_idx] * rows_norms)
-        # make sure normalization vector is of the same shape of projection
-        normalization = tl.reshape(normalization, tl.shape(projection))
-        projection = projection / normalization
+        projection = projection / (tl.sum(max_row**2))
 
         # Subtract the projection from A_new:  b <- b - a * projection
-        A_new = A_new - A_new * tl.reshape(projection, (tl.shape(A_new)[0], 1))
+        A_new = A_new - tl.tenalg.outer((projection, max_row))
 
         # Delete the selected row
         mask.pop(tl.to_numpy(max_row_idx))