# A.I.M.S algorithms

DecompositionTQLI< T > Class Template Reference

`#include <aims/math/tqli.h>`

## Public Member Functions

void doit (AimsData< T > &, AimsData< T > &, AimsData< T > &)
TQLI decomposition of a tridiagonal matrix. More...

DecompositionTQLI ()
Constructor and destructor. More...

virtual ~DecompositionTQLI ()
destructor More...

## Detailed Description

### template<class T> class DecompositionTQLI< T >

Definition at line 45 of file tqli.h.

## Constructor & Destructor Documentation

template<class T >
 DecompositionTQLI< T >::DecompositionTQLI ( )
inline

Constructor and destructor.

constructor

Definition at line 52 of file tqli.h.

template<class T >
 virtual DecompositionTQLI< T >::~DecompositionTQLI ( )
inlinevirtual

destructor

Definition at line 54 of file tqli.h.

## Member Function Documentation

template<class T >
 void DecompositionTQLI< T >::doit ( AimsData< T > & , AimsData< T > & , AimsData< T > & )

TQLI decomposition of a tridiagonal matrix.

\ This function is adapted from the Numerical Recipes in C. \ This routine determines the eigenvalues and eigenvectors of a real, symmetric, tridiagonal matrix, or of a real, symmetric matrix previously reduced by HouseholderTridiag. \ The first parameter contains (on input) the diagonal elements of the tridiagonal matrix. On output, it is replaced by the eigenvalues. \ The second parameter is the vector of the subdiagonal elements of the tridiagonal matrix. \ The last parameter is set (on input) as an identity matrix if the eigenvectors of a tridiagonal matrix are desired, or as the matrix output by HouseholderTridiag if the matrix was previously reduced. On output, it is replaced by the normalized eigenvectors. The k-th column of this matrix corresponds to the k-th eigenvector.

The documentation for this class was generated from the following file: