Tutorial page 4: add some text, diversify examples.

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Give tables consistent look.

doc/examples/Tutorial_BlockOperations_block_assignment.cpp

@@ -6,26 +6,13 @@ using namespace Eigen;
 
 int main()
 {
-  MatrixXf m(3,3), n(2,2);
-  
+  Array33f m;
   m << 1,2,3,
        4,5,6,
        7,8,9;
-       
-  // assignment through a block operation,
-  //  block as rvalue
-  n = m.block(0,0,2,2);
-  
-  //print n
+  Array<float,5,5> n = Array<float,5,5>::Constant(0.6);
+  n.block(1,1,3,3) = m;
   cout << "n = " << endl << n << endl << endl;
-  
-  
-  n << 1,1,
-       1,1;
-        
-  // block as lvalue
-  m.block(0,0,2,2) = n;
-  
-  //print m
-  cout << "m = " << endl << m << endl;
+  Array33f res = n.block(0,0,3,3) * m;
+  cout << "res =" << endl << res << endl;
 }

doc/examples/Tutorial_BlockOperations_colrow.cpp

@@ -1,15 +1,14 @@
 #include <Eigen/Dense>
 #include <iostream>
-using namespace Eigen;
 
 int main()
 {
-  MatrixXf m(3,3);
-  
+  Eigen::MatrixXf m(3,3);
   m << 1,2,3,
        4,5,6,
        7,8,9;
-     
-  std::cout << "2nd Row: "
-    << m.row(1) << std::endl;
+  std::cout << "2nd Row: " << m.row(1) << std::endl;
+  m.col(0) += m.col(2);
+  std::cout << "m after adding third column to first:\n";
+  std::cout << m << std::endl;
 }

doc/examples/Tutorial_BlockOperations_corner.cpp

@@ -2,26 +2,16 @@
 #include <iostream>
 
 using namespace std;
-using namespace Eigen;
 
 int main()
 {
-  MatrixXf m(4,4);
-  
+  Eigen::Matrix4f m;
   m << 1, 2, 3, 4,
        5, 6, 7, 8,
        9, 10,11,12,
        13,14,15,16;
-
-  //print first two columns
-  cout << "-- leftCols(2) --" << endl
-    << m.leftCols(2) << endl << endl;
-  
-  //print last two rows
-  cout << "-- bottomRows(2) --" << endl
-    << m.bottomRows(2) << endl << endl;
-    
-  //print top-left 2x3 corner
-  cout << "-- topLeftCorner(2,3) --" << endl
-    << m.topLeftCorner(2,3) << endl;
+  cout << "m.leftCols(2) =" << endl << m.leftCols(2) << endl << endl;
+  cout << "m.bottomRows<2>() =" << endl << m.bottomRows<2>() << endl << endl;
+  m.topLeftCorner(1,3) = m.bottomRightCorner(3,1).transpose();
+  cout << "After assignment, m = " << endl << m << endl;
 }

doc/examples/Tutorial_BlockOperations_print_block.cpp

@@ -1,14 +1,18 @@
 #include <Eigen/Dense>
 #include <iostream>
-using namespace Eigen;
 
 int main()
 {
-  MatrixXf m(3,3);
-  
-  m << 1,2,3,
-       4,5,6,
-       7,8,9;
-     
-  std::cout << m.block(0,0,2,2) << std::endl;
+  Eigen::MatrixXf m(4,4);
+  m <<  1, 2, 3, 4,
+        5, 6, 7, 8,
+        9,10,11,12,
+       13,14,15,16;
+  std::cout << "Block in the middle" << std::endl;
+  std::cout << m.block<2,2>(1,1) << std::endl << std::endl;
+  for (int i = 1; i < 4; ++i) 
+  {
+    std::cout << "Block of size " << i << std::endl;
+    std::cout << m.block(0,0,i,i) << std::endl << std::endl;
+  }
 }

doc/examples/Tutorial_BlockOperations_vector.cpp

@@ -2,23 +2,13 @@
 #include <iostream>
 
 using namespace std;
-using namespace Eigen;
 
 int main()
 {
-  VectorXf v(6);
-  
+  Eigen::ArrayXf v(6);
   v << 1, 2, 3, 4, 5, 6;
-
-  //print first three elements
-  cout << "-- head(3) --" << endl
-    << v.head(3) << endl << endl;
-  
-  //print last three elements
-  cout << "-- tail(3) --" << endl
-    << v.tail(3) << endl << endl;
-    
-  //print between 2nd and 5th elem. inclusive
-  cout << "-- segment(1,4) --" << endl
-    << v.segment(1,4) << endl;
+  cout << "v.head(3) =" << endl << v.head(3) << endl << endl;
+  cout << "v.tail<3>() = " << endl << v.tail<3>() << endl << endl;
+  v.segment(1,4) *= 2;
+  cout << "after 'v.segment(1,4) *= 2', v =" << endl << v << endl;
 }