- rework the coefficients API

- make vectors use a separate loop unroller, so that copying a
row-vector into a col-vector is now possible
- add much more documentation
- misc improvements

doc/examples/class_Block.cpp

@@ -0,0 +1,23 @@
+#include <Eigen/Core.h>
+USING_PART_OF_NAMESPACE_EIGEN
+using namespace std;
+
+template<typename Scalar, typename Derived>
+Eigen::Block<Derived, 2, 2>
+topLeft2x2Corner(MatrixBase<Scalar, Derived>& m)
+{
+  return Eigen::Block<Derived, 2, 2>(m.ref(), 0, 0);
+  // note: tempting as it is, writing "m.block<2,2>(0,0)" here
+  // causes a compile error with g++ 4.2, apparently due to
+  // g++ getting confused by the many template types and
+  // template arguments involved.
+}
+
+int main(int, char**)
+{
+  Matrix3d m = Matrix3d::identity();
+  cout << topLeft2x2Corner(m) << endl;
+  topLeft2x2Corner(m) *= 2;
+  cout << "Now the matrix m is:" << endl << m << endl;
+  return 0;
+}

doc/examples/class_Cast.cpp

@@ -0,0 +1,23 @@
+#include <Eigen/Core.h>
+USING_PART_OF_NAMESPACE_EIGEN
+using namespace std;
+
+template<typename Scalar, typename Derived>
+Eigen::Cast<double, Derived>
+castToDouble(const MatrixBase<Scalar, Derived>& m)
+{
+  return Eigen::Cast<double, Derived>(m.ref());
+  // note: tempting as it is, writing "m.cast<double>()" here
+  // causes a compile error with g++ 4.2, apparently due to
+  // g++ getting confused by the many template types and
+  // template arguments involved.
+}
+
+int main(int, char**)
+{
+  Matrix2i m = Matrix2i::random();
+  cout << "Here's the matrix m. It has coefficients of type int."
+       << endl << m << endl;
+  cout << "Here's 0.05*m:" << endl << 0.05 * castToDouble(m) << endl;
+  return 0;
+}

doc/examples/class_Column.cpp

@@ -0,0 +1,19 @@
+#include <Eigen/Core.h>
+USING_PART_OF_NAMESPACE_EIGEN
+using namespace std;
+
+template<typename Scalar, typename Derived>
+Eigen::Column<Derived>
+firstColumn(MatrixBase<Scalar, Derived>& m)
+{
+  return m.col(0);
+}
+
+int main(int, char**)
+{
+  Matrix4d m = Matrix4d::identity();
+  cout << firstColumn(m) << endl;
+  firstColumn(m) *= 5;
+  cout << "Now the matrix m is:" << endl << m << endl;
+  return 0;
+}

doc/examples/class_DynBlock.cpp

@@ -1,10 +1,10 @@
 #include <Eigen/Core.h>
-USING_EIGEN_DATA_TYPES
+USING_PART_OF_NAMESPACE_EIGEN
 using namespace std;
 
 template<typename Scalar, typename Derived>
 Eigen::DynBlock<Derived>
-topLeftCorner(const Eigen::MatrixBase<Scalar, Derived>& m, int rows, int cols)
+topLeftCorner(MatrixBase<Scalar, Derived>& m, int rows, int cols)
 {
   return m.dynBlock(0, 0, rows, cols);
 }

doc/examples/class_Row.cpp

@@ -0,0 +1,19 @@
+#include <Eigen/Core.h>
+USING_PART_OF_NAMESPACE_EIGEN
+using namespace std;
+
+template<typename Scalar, typename Derived>
+Eigen::Row<Derived>
+firstRow(MatrixBase<Scalar, Derived>& m)
+{
+  return m.row(0);
+}
+
+int main(int, char**)
+{
+  Matrix4d m = Matrix4d::identity();
+  cout << firstRow(m) << endl;
+  firstRow(m) *= 5;
+  cout << "Now the matrix m is:" << endl << m << endl;
+  return 0;
+}