trac #16032: These matrices should be sparse

sagemath · Mar 31, 2014 · f6da4b7 · f6da4b7
1 parent 7dcff95
commit f6da4b7
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/sage/combinat/designs/incidence_structures.py b/src/sage/combinat/designs/incidence_structures.py
@@ -491,7 +491,7 @@ def incidence_matrix(self):
             v = len(self.points())
             blks = self.blocks()
             b = len(blks)
-            A = Matrix(ZZ, v, b)
+            A = Matrix(ZZ, v, b, sparse=True)
             for j, b in enumerate(blks):
                 for i in b:
                     A[i, j] = 1