RWEigDecomp<T>

Module:  Linear Algebra   Group:  Nonsymmetric Eigenvalue Decomposition classes

Does not inherit

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• Synopsis
• Description
• Example
• Public Constructors
• Public Member Functions
• Public Member Operator

Members

cols() eigenValue() eigenValues() factor() fail()

good() inaccurate() leftEigenVector() leftEigenVectors() numEigenValues()

numLeftEigenVectors() numRightEigenVectors() operator=() rightEigenVector() rightEigenVectors()

rows() RWEigDecomp<DComplex>() RWEigDecomp<T>() RWEigDecomp()

#include <rw/lapack/eig.h>

RWEigDecomp<double> eig(A);      // A is an
                                  // RWGenMat<double>

The class RWEigDecomp<T> encapsulates the eigenvalues and eigenvectors of a nonsymmetric matrix. You can construct an eigenvalue decomposition object in two ways:

• Use the decomposition class constructor. This has the advantage of simplicity, but allows only limited control over the computation. Your only choice is whether or not to compute eigenvectors.

• Use an eigenvalue server object. This gives you more precise control over the computation. See RWEigServer<T> in this manual for details.

#include <iostream>
#include <rw/lapack/eig.h>

int main()
{
   RWGenMat<double> A;
   std::cin >> A;
   RWEigDecomp<double> eig(A);
   std::cout << "eigenvalues: " << eig.eigenValues() <<
                std::endl;
   std::cout << "left eigenvectors: " << eig.leftEigenVectors() 
              << std::endl;
   std::cout << "right vectors: " << eig.rightEigenVectors() << endl;
   return 0;
}

RWEigDecomp();

Default constructor. Builds a decomposition of a 0 x 0 matrix.

RWEigDecomp<T>(const RWEigDecomp<T>& A);
RWEigDecomp<DComplex>(const RWEigDecomp<double>& A);

Copy and precision conversion constructors. Where possible, data is referenced for efficiency.

RWEigDecomp(const RWGenMat<T>& A,
    bool computeVecs=true);

Constructs a representation of the eigenvalues and eigenvectors of the matrix A. The boolean parameter controls whether eigenvectors are computed.

unsigned
cols();

Returns the number of columns in the decomposed matrix.

DComplex
eigenValue(int i) const;

Returns the i^th eigenvalue.

RWMathVec<DComplex>
eigenValues() const;

Returns a vector of all computed eigenvalues.

void
factor(const RWGenMat<T>& A,
      bool computeVecs=true);

Constructs a representation of the eigenvalues and eigenvectors of the matrix A. The boolean parameter controls whether eigenvectors are computed. The current contents of the decomposition are lost.

bool
fail() const;

Returns true if an eigenvalue or eigenvector that is supposed to be computed fails to be computed.

bool
good() const;

Returns true if all desired eigenvalues and eigenvectors are successfully computed to full desired accuracy.

bool
inaccurate() const;

Returns true if either an eigenvalue or eigenvector that is supposed to be computed fails to be computed, or some of the computed quantities are not computed to full desired accuracy.

RWMathVec<DComplex>
leftEigenVector(int i) const;

Returns the i^th left eigenvector.

RWGenMat<DComplex>
leftEigenVectors() const;

Returns a vector of all computed left eigenvectors.

unsigned 
numEigenValues() const;
unsigned 
numLeftEigenVectors() const;
unsigned 
numRightEigenVectors() const;

Returns the number of eigenvalues or eigenvectors represented in this object.

RWMathVec<DComplex>
rightEigenVector(int i) const;

Returns the i^th right eigenvector.

RWGenMat<DComplex>
rightEigenVectors() const;

Returns a matrix of all computed right eigenvectors.

unsigned
rows();

Returns the number of rows in the decomposed matrix.

void   operator=(const RWEigDecomp<T>&);

Assigns the passed value to this decomposition. The current contents of the decomposition are lost.

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