Add support for matrix sine, cosine, sinh and cosh.

unsupported/doc/examples/MatrixSinh.cpp

@@ -0,0 +1,21 @@
+#include <unsupported/Eigen/MatrixFunctions>
+
+using namespace Eigen;
+
+int main()
+{
+  MatrixXf A = MatrixXf::Random(3,3);
+  std::cout << "A = \n" << A << "\n\n";
+
+  MatrixXf sinhA;
+  ei_matrix_sinh(A, &sinhA);
+  std::cout << "sinh(A) = \n" << sinhA << "\n\n";
+
+  MatrixXf coshA;
+  ei_matrix_cosh(A, &coshA);
+  std::cout << "cosh(A) = \n" << coshA << "\n\n";
+  
+  // The matrix functions satisfy cosh^2(A) - sinh^2(A) = I, 
+  // like the scalar functions.
+  std::cout << "cosh^2(A) - sinh^2(A) = \n" << coshA*coshA - sinhA*sinhA << "\n\n";
+}