Squashed 'third_party/eigen/' content from commit 61d72f6
Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/doc/snippets/TopicAliasing_cwise.cpp b/doc/snippets/TopicAliasing_cwise.cpp
new file mode 100644
index 0000000..7049f6c
--- /dev/null
+++ b/doc/snippets/TopicAliasing_cwise.cpp
@@ -0,0 +1,20 @@
+MatrixXf mat(2,2);
+mat << 1, 2, 4, 7;
+cout << "Here is the matrix mat:\n" << mat << endl << endl;
+
+mat = 2 * mat;
+cout << "After 'mat = 2 * mat', mat = \n" << mat << endl << endl;
+
+
+mat = mat - MatrixXf::Identity(2,2);
+cout << "After the subtraction, it becomes\n" << mat << endl << endl;
+
+
+ArrayXXf arr = mat;
+arr = arr.square();
+cout << "After squaring, it becomes\n" << arr << endl << endl;
+
+// Combining all operations in one statement:
+mat << 1, 2, 4, 7;
+mat = (2 * mat - MatrixXf::Identity(2,2)).array().square();
+cout << "Doing everything at once yields\n" << mat << endl << endl;