add vcglib

vcglib/eigenlib/unsupported/doc/examples/MatrixLogarithm.cpp

@@ -0,0 +1,15 @@
+#include <unsupported/Eigen/MatrixFunctions>
+#include <iostream>
+
+using namespace Eigen;
+
+int main()
+{
+  using std::sqrt;
+  MatrixXd A(3,3);
+  A << 0.5*sqrt(2), -0.5*sqrt(2), 0,
+       0.5*sqrt(2),  0.5*sqrt(2), 0,
+       0,            0,           1;
+  std::cout << "The matrix A is:\n" << A << "\n\n";
+  std::cout << "The matrix logarithm of A is:\n" << A.log() << "\n";
+}