update

1 files changed, 20 insertions, 0 deletions

diff --git a/eigen/doc/snippets/Tutorial_AdvancedInitialization_ThreeWays.cpp b/eigen/doc/snippets/Tutorial_AdvancedInitialization_ThreeWays.cpp
new file mode 100644
index 0000000..cb74576
--- /dev/null
+++ b/eigen/doc/snippets/Tutorial_AdvancedInitialization_ThreeWays.cpp
@@ -0,0 +1,20 @@
+const int size = 6;
+MatrixXd mat1(size, size);
+mat1.topLeftCorner(size/2, size/2)     = MatrixXd::Zero(size/2, size/2);
+mat1.topRightCorner(size/2, size/2)    = MatrixXd::Identity(size/2, size/2);
+mat1.bottomLeftCorner(size/2, size/2)  = MatrixXd::Identity(size/2, size/2);
+mat1.bottomRightCorner(size/2, size/2) = MatrixXd::Zero(size/2, size/2);
+std::cout << mat1 << std::endl << std::endl;
+
+MatrixXd mat2(size, size);
+mat2.topLeftCorner(size/2, size/2).setZero();
+mat2.topRightCorner(size/2, size/2).setIdentity();
+mat2.bottomLeftCorner(size/2, size/2).setIdentity();
+mat2.bottomRightCorner(size/2, size/2).setZero();
+std::cout << mat2 << std::endl << std::endl;
+
+MatrixXd mat3(size, size);
+mat3 << MatrixXd::Zero(size/2, size/2), MatrixXd::Identity(size/2, size/2),
+        MatrixXd::Identity(size/2, size/2), MatrixXd::Zero(size/2, size/2);
+std::cout << mat3 << std::endl;
+