Description of tri

tri_solve		Programmers Guide
		Contents \| Index \| Search

Category:algorithms

Component type:function

Prototype

template <class TriMatrix, class VecX> void tri_solve(const TriMatrix& T, VecX x) ;

Description

Use with trianguler matrixes only ie. use the triangle adaptor class. To use with a sparse matrix, the sparse matrix must be wrapped with a triangle adaptor. You must specify "packed" in the triangle adaptor. The sparse matrix must only have elements in the correct side.

Definition

mtl.h

Requirements on types

Matrix::value_type and VecX::value_type must be the same type
the multiplication operator must be defined for Matrix::value_type
the division operator must be defined for Matrix::value_type
the addition operator must be defined for Matrix::value_type

Preconditions

Complexity

Example

In tri_solve.cc:


  typedef matrix< double, 
                  triangle<lower>,
                   packed<>, 
                   row_major >::type Matrix;
  typedef external_vec<double> Vector;
  const int N = 3;

  Matrix A(N, N);

  set_diagonal(A, 1);

  //Fill the matrix...

  A(1,0) = 2;  A(1,1) = 4;
  A(2,0) = 3;  A(2,1) = 5; A(2,2) = 6;

  double db[] = { 7, 46, 115};
  Vector b(db, N);

  cout << "A in packed form" << endl;
  print_row(A);

  cout << "b:" << endl;
  print_vector(b);

  tri_solve(A, b);

  cout << "A^-1 * b:" << endl;

  print_vector(b);

Notes

See also