big improvements to tutorial, especially page 2 (matrix arithmetic).

add placeholders for some 'special topic' pages.

doc/examples/tut_arithmetic_add_sub.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+#include <Eigen/Dense>
+
+using namespace Eigen;
+
+int main()
+{
+  Matrix2d a;
+  a << 1, 2,
+       3, 4;
+  MatrixXd b(2,2);
+  b << 2, 3,
+       1, 4;
+  std::cout << "a + b =\n" << a + b << std::endl;
+  std::cout << "a - b =\n" << a - b << std::endl;
+  std::cout << "Doing a += b;" << std::endl;
+  a += b;
+  std::cout << "Now a =\n" << a << std::endl;
+  Vector3d v(1,2,3);
+  Vector3d w(1,0,0);
+  std::cout << "-v + w - v =\n" << -v + w - v << std::endl;
+}

doc/examples/tut_arithmetic_dot_cross.cpp

@@ -0,0 +1,12 @@
+#include <iostream>
+#include <Eigen/Dense>
+
+using namespace Eigen;
+int main()
+{
+  Vector3d v(1,2,3);
+  Vector3d w(0,1,2);
+
+  std::cout << "Dot product: " << v.dot(w) << std::endl;
+  std::cout << "Cross product:\n" << v.cross(w) << std::endl;
+}

doc/examples/tut_arithmetic_matrix_mul.cpp

@@ -0,0 +1,19 @@
+#include <iostream>
+#include <Eigen/Dense>
+
+using namespace Eigen;
+int main()
+{
+  Matrix2d mat;
+  mat << 1, 2,
+         3, 4;
+  Vector2d vec(-1,1);
+  RowVector2d rowvec(2,0);
+  std::cout << "Here is mat*mat:\n" << mat*mat << std::endl;
+  std::cout << "Here is mat*vec:\n" << mat*vec << std::endl;
+  std::cout << "Here is rowvec*mat:\n" << rowvec*mat << std::endl;
+  std::cout << "Here is rowvec*vec:\n" << rowvec*vec << std::endl;
+  std::cout << "Here is vec*rowvec:\n" << vec*rowvec << std::endl;
+  std::cout << "Let's multiply mat by itself" << std::endl;
+  std::cout << "Now mat is mat:\n" << mat << std::endl;
+}

doc/examples/tut_arithmetic_scalar_mul_div.cpp

@@ -0,0 +1,17 @@
+#include <iostream>
+#include <Eigen/Dense>
+
+using namespace Eigen;
+
+int main()
+{
+  Matrix2d a;
+  a << 1, 2,
+       3, 4;
+  Vector3d v(1,2,3);
+  std::cout << "a * 2.5 =\n" << a * 2.5 << std::endl;
+  std::cout << "0.1 * v =\n" << 0.1 * v << std::endl;
+  std::cout << "Doing v *= 2;" << std::endl;
+  v *= 2;
+  std::cout << "Now v =\n" << v << std::endl;
+}