Fix and test

pacman/model/graphs/common/mdslice.py

@@ -159,23 +159,23 @@ def from_string(cls, as_str):
     def get_relative_indices(self, app_vertex_indices):
         n_dims = len(self._atoms_shape)
         remainders = app_vertex_indices
-        last_per_core = 0
+        cum_last_core = 1
         rel_index = numpy.zeros(len(app_vertex_indices))
-        for n in n_dims:
+        for n in range(n_dims):
             # Work out the index in this dimension
             global_index_d = remainders % self._atoms_shape[n]
 
             # Work out the index in this dimension relative to the core start
-            rel_index_d = global_index_d - self._starts[n]
+            rel_index_d = global_index_d - self._start[n]
 
             # Update the total relative index using the position in this
             # dimension
-            rel_index = (rel_index * last_per_core) + rel_index_d
+            rel_index += rel_index_d * cum_last_core
 
             # Prepare for next round of the loop by removing what we used
             # of the global index and remembering the sizes in this
             # dimension
             remainders = remainders // self._atoms_shape[n]
-            last_per_core = self._shape[n]
+            cum_last_core *= self._shape[n]
 
-        return rel_index
+        return rel_index.astype(numpy.uint32)

unittests/model_tests/test_mdslice.py

@@ -76,3 +76,10 @@ def test_3b(self):
                              list(s.get_raster_ids()))
         s2 = MDSlice.from_string(str(s))
         self.assertEqual(s, s2)
+
+    def test_get_relative_indices(self):
+        s = MDSlice(22, 89, (2, 3, 2), (4, 3, 0), (6, 9, 4))
+        # Going over the raster IDs should result in a line over the core
+        self.assertListEqual(list(range(2 * 3 * 2)),
+                             list((s.get_relative_indices(
+                                 s.get_raster_ids()))))