remove contract() deprecation warning in step-9

diff --git a/examples/step-9/step-9.cc b/examples/step-9/step-9.cc
index 8b6a8dd0d13138a65ccc185555a4e79f51314727..1919ffcea4d13fb34b2056fd3e4c386a31e228df 100644 (file)
--- a/examples/step-9/step-9.cc
+++ b/examples/step-9/step-9.cc
@@ -1297,8 +1297,7 @@ namespace Step9
     // using this quantity and the right powers of the mesh width:
     const Tensor<2,dim> Y_inverse = invert(Y);
 
-    Tensor<1,dim> gradient;
-    contract (gradient, Y_inverse, projected_gradient);
+    Tensor<1,dim> gradient = Y_inverse * projected_gradient;
 
     // The last part of this function is the one where we
     // write into the element of the output vector what