Use an aligned IOFormat in the docs

Eigen/src/Core/util/Macros.h

@@ -118,6 +118,10 @@ using Eigen::ei_cos;
 #define EIGEN_DEFAULT_IO_FORMAT Eigen::IOFormat()
 #endif
 
+// format used in Eigen's documentation
+// needed to define it here as escaping characters in CMake add_definition's argument seems very problematic.
+#define EIGEN_DOCS_IO_FORMAT IOFormat(3, AlignCols, " ", "\n", "", "")
+
 #define EIGEN_INHERIT_ASSIGNMENT_OPERATOR(Derived, Op) \
 template<typename OtherDerived> \
 Derived& operator Op(const Eigen::MatrixBase<OtherDerived>& other) \

doc/CMakeLists.txt

@@ -25,6 +25,8 @@ configure_file(
 set(examples_targets "")
 set(snippets_targets "")
 
+add_definitions("-DEIGEN_DEFAULT_IO_FORMAT=EIGEN_DOCS_IO_FORMAT")
+
 add_subdirectory(examples)
 add_subdirectory(snippets)
 

doc/TutorialLinearAlgebra.dox

@@ -158,8 +158,11 @@ Eigen::LUDecomposition<MatrixXf> lu(A);
 cout << "The rank of A is" << lu.rank() << endl;
 if(lu.isInvertible()) {
   cout << "A is invertible, its inverse is:" << endl << lu.inverse() << endl;
+}
+else {
   cout << "Here's a matrix whose columns form a basis of the kernel a.k.a. nullspace of A:"
        << endl << lu.kernel() << endl;
+}
 \endcode
 
 \sa LU_Module, LU::solve(), class LU

doc/snippets/compile_snippet.cpp.in

@@ -4,13 +4,11 @@
 #include <Eigen/Cholesky>
 #include <Eigen/Geometry>
 
-USING_PART_OF_NAMESPACE_EIGEN
 using namespace Eigen;
 using namespace std;
 
 int main(int, char**)
 {
-  cout.precision(3);
   ${snippet_source_code}
   return 0;
 }