[T] Add autocheck random Eigen matrices generator.

Tests/MathLib/AutoCheckTools.h

@@ -9,7 +9,8 @@
 #ifndef TESTS_MATHLIB_AUTOCHECKTOOLS_H_
 #define TESTS_MATHLIB_AUTOCHECKTOOLS_H_
 
-#include "autocheck/autocheck.hpp"
+#include <Eigen/Dense>
+#include <autocheck/autocheck.hpp>
 
 #include "MathLib/Point3d.h"
 
@@ -67,6 +68,22 @@ struct IntervalTupleGenerator
     }
 };
 
+/// Generator for MxN fixed size eigen matrices with underlying type T.
+template <typename T, std::size_t M, std::size_t N, typename Gen = generator<T>>
+struct randomEigenMatrixGenerator
+{
+    Gen source;
+
+    using result_type = Eigen::Matrix<T, M, N>;
+
+    result_type operator()(std::size_t size = 0)
+    {
+        result_type rv;
+        std::generate_n(rv.data(), M*N, fix(size, source));
+        return rv;
+    }
+};
+
 template <typename T, std::size_t N, typename Gen = generator<T>>
 struct randomTupleGenerator
 {