nearly complete page 6 / linear algebra + examples

fix the previous/next links

1 files changed, 14 insertions, 0 deletions

diff --git a/doc/examples/TutorialLinAlgExComputeSolveError.cpp b/doc/examples/TutorialLinAlgExComputeSolveError.cpp
new file mode 100644
index 000000000..f362fb71a
--- /dev/null
+++ b/doc/examples/TutorialLinAlgExComputeSolveError.cpp
@@ -0,0 +1,14 @@
+#include <iostream>
+#include <Eigen/Dense>
+
+using namespace std;
+using namespace Eigen;
+
+int main()
+{
+   MatrixXd A = MatrixXd::Random(100,100);
+   MatrixXd b = MatrixXd::Random(100,50);
+   MatrixXd x = A.fullPivLu().solve(b);
+   double relative_error = (A*x - b).norm() / b.norm(); // norm() is L2 norm
+   cout << "The relative error is:\n" << relative_error << endl;
+}