diff --git a/doc/snippets/PartialRedux_sum.cpp b/doc/snippets/PartialRedux_sum.cpp
new file mode 100644
index 0000000..ec82d3e
--- /dev/null
+++ b/doc/snippets/PartialRedux_sum.cpp
@@ -0,0 +1,3 @@
+Matrix3d m = Matrix3d::Random();
+cout << "Here is the matrix m:" << endl << m << endl;
+cout << "Here is the sum of each row:" << endl << m.rowwise().sum() << endl;