Merge pull request scipy#367 from kclawson/bug-fixes

Fix for ticket scipy#1604

Author: jakevdp

scipy/sparse/compressed.py

@@ -378,7 +378,7 @@ def _get_single_element(self,row,col):
 
         if num_matches == 0:
             # entry does not appear in the matrix
-            return 0
+            return self.dtype.type(0)
         elif num_matches == 1:
             return self.data[start:end][indxs[0]]
         else:

scipy/sparse/lil.py

@@ -193,9 +193,9 @@ def _get1(self, i, j):
 
         pos = bisect_left(row, j)
         if pos != len(data) and row[pos] == j:
-            return data[pos]
+            return self.dtype.type(data[pos])
         else:
-            return 0
+            return self.dtype.type(0)
 
     def _slicetoseq(self, j, shape):
         if j.start is not None and j.start < 0:
@@ -328,7 +328,7 @@ def __setitem__(self, index, x):
         if isspmatrix(x):
             if isinstance(i, slice) and i == slice(None) and \
                isinstance(j, slice) and j == slice(None):
-                x = lil_matrix(x)
+                x = lil_matrix(x, dtype=self.dtype)
                 self.rows = x.rows
                 self.data = x.data
                 return

scipy/sparse/tests/test_base.py

@@ -1609,6 +1609,11 @@ def test_inplace_ops(self):
 
             assert_array_equal(result.todense(), expected.todense())
 
+        # Ticket 1604. 
+        A = lil_matrix((1,3), dtype=np.dtype('float64'))
+        B = array([0.1,0.1,0.1])
+        A[0,:] += B
+        assert_array_equal(A[0,:].toarray().squeeze(), B)
 
     def test_lil_slice_assignment(self):
         B = lil_matrix((4,3))