From f0238cfb6997c4acfc2bd200de7295f3fa36968f Mon Sep 17 00:00:00 2001
From: Stanislaw Halik <sthalik@misaki.pl>
Date: Sun, 3 Mar 2019 21:09:10 +0100
Subject: don't index Eigen

---
 eigen/doc/examples/matrixfree_cg.cpp | 129 -----------------------------------
 1 file changed, 129 deletions(-)
 delete mode 100644 eigen/doc/examples/matrixfree_cg.cpp

(limited to 'eigen/doc/examples/matrixfree_cg.cpp')

diff --git a/eigen/doc/examples/matrixfree_cg.cpp b/eigen/doc/examples/matrixfree_cg.cpp
deleted file mode 100644
index 7469938..0000000
--- a/eigen/doc/examples/matrixfree_cg.cpp
+++ /dev/null
@@ -1,129 +0,0 @@
-#include <iostream>
-#include <Eigen/Core>
-#include <Eigen/Dense>
-#include <Eigen/IterativeLinearSolvers>
-#include <unsupported/Eigen/IterativeSolvers>
-
-class MatrixReplacement;
-using Eigen::SparseMatrix;
-
-namespace Eigen {
-namespace internal {
-  // MatrixReplacement looks-like a SparseMatrix, so let's inherits its traits:
-  template<>
-  struct traits<MatrixReplacement> :  public Eigen::internal::traits<Eigen::SparseMatrix<double> >
-  {};
-}
-}
-
-// Example of a matrix-free wrapper from a user type to Eigen's compatible type
-// For the sake of simplicity, this example simply wrap a Eigen::SparseMatrix.
-class MatrixReplacement : public Eigen::EigenBase<MatrixReplacement> {
-public:
-  // Required typedefs, constants, and method:
-  typedef double Scalar;
-  typedef double RealScalar;
-  typedef int StorageIndex;
-  enum {
-    ColsAtCompileTime = Eigen::Dynamic,
-    MaxColsAtCompileTime = Eigen::Dynamic,
-    IsRowMajor = false
-  };
-
-  Index rows() const { return mp_mat->rows(); }
-  Index cols() const { return mp_mat->cols(); }
-
-  template<typename Rhs>
-  Eigen::Product<MatrixReplacement,Rhs,Eigen::AliasFreeProduct> operator*(const Eigen::MatrixBase<Rhs>& x) const {
-    return Eigen::Product<MatrixReplacement,Rhs,Eigen::AliasFreeProduct>(*this, x.derived());
-  }
-
-  // Custom API:
-  MatrixReplacement() : mp_mat(0) {}
-
-  void attachMyMatrix(const SparseMatrix<double> &mat) {
-    mp_mat = &mat;
-  }
-  const SparseMatrix<double> my_matrix() const { return *mp_mat; }
-
-private:
-  const SparseMatrix<double> *mp_mat;
-};
-
-
-// Implementation of MatrixReplacement * Eigen::DenseVector though a specialization of internal::generic_product_impl:
-namespace Eigen {
-namespace internal {
-
-  template<typename Rhs>
-  struct generic_product_impl<MatrixReplacement, Rhs, SparseShape, DenseShape, GemvProduct> // GEMV stands for matrix-vector
-  : generic_product_impl_base<MatrixReplacement,Rhs,generic_product_impl<MatrixReplacement,Rhs> >
-  {
-    typedef typename Product<MatrixReplacement,Rhs>::Scalar Scalar;
-
-    template<typename Dest>
-    static void scaleAndAddTo(Dest& dst, const MatrixReplacement& lhs, const Rhs& rhs, const Scalar& alpha)
-    {
-      // This method should implement "dst += alpha * lhs * rhs" inplace,
-      // however, for iterative solvers, alpha is always equal to 1, so let's not bother about it.
-      assert(alpha==Scalar(1) && "scaling is not implemented");
-      EIGEN_ONLY_USED_FOR_DEBUG(alpha);
-
-      // Here we could simply call dst.noalias() += lhs.my_matrix() * rhs,
-      // but let's do something fancier (and less efficient):
-      for(Index i=0; i<lhs.cols(); ++i)
-        dst += rhs(i) * lhs.my_matrix().col(i);
-    }
-  };
-
-}
-}
-
-int main()
-{
-  int n = 10;
-  Eigen::SparseMatrix<double> S = Eigen::MatrixXd::Random(n,n).sparseView(0.5,1);
-  S = S.transpose()*S;
-
-  MatrixReplacement A;
-  A.attachMyMatrix(S);
-
-  Eigen::VectorXd b(n), x;
-  b.setRandom();
-
-  // Solve Ax = b using various iterative solver with matrix-free version:
-  {
-    Eigen::ConjugateGradient<MatrixReplacement, Eigen::Lower|Eigen::Upper, Eigen::IdentityPreconditioner> cg;
-    cg.compute(A);
-    x = cg.solve(b);
-    std::cout << "CG:       #iterations: " << cg.iterations() << ", estimated error: " << cg.error() << std::endl;
-  }
-
-  {
-    Eigen::BiCGSTAB<MatrixReplacement, Eigen::IdentityPreconditioner> bicg;
-    bicg.compute(A);
-    x = bicg.solve(b);
-    std::cout << "BiCGSTAB: #iterations: " << bicg.iterations() << ", estimated error: " << bicg.error() << std::endl;
-  }
-
-  {
-    Eigen::GMRES<MatrixReplacement, Eigen::IdentityPreconditioner> gmres;
-    gmres.compute(A);
-    x = gmres.solve(b);
-    std::cout << "GMRES:    #iterations: " << gmres.iterations() << ", estimated error: " << gmres.error() << std::endl;
-  }
-
-  {
-    Eigen::DGMRES<MatrixReplacement, Eigen::IdentityPreconditioner> gmres;
-    gmres.compute(A);
-    x = gmres.solve(b);
-    std::cout << "DGMRES:   #iterations: " << gmres.iterations() << ", estimated error: " << gmres.error() << std::endl;
-  }
-
-  {
-    Eigen::MINRES<MatrixReplacement, Eigen::Lower|Eigen::Upper, Eigen::IdentityPreconditioner> minres;
-    minres.compute(A);
-    x = minres.solve(b);
-    std::cout << "MINRES:   #iterations: " << minres.iterations() << ", estimated error: " << minres.error() << std::endl;
-  }
-}
-- 
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