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/*
ARPACK++ v1.2 2/18/2000
c++ interface to ARPACK code.
MODULE DCompGRe.cc.
Example program that illustrates how to solve a complex dense
generalized eigenvalue problem in regular mode using the
ARluCompGenEig class.
1) Problem description:
In this example we try to solve A*x = B*x*lambda in regular mode,
where A and B are derived from the finite element discretization
of the 1-dimensional convection-diffusion operator
(d^2u/dx^2) + rho*(du/dx)
on the interval [0,1], with zero boundary conditions, using
piecewise linear elements.
2) Data structure used to represent matrices A and B:
Although A and B are very sparse in this example, they are
stored here as dense matrices (by columns).
3) Library called by this example:
The LAPACK package is called by ARluCompGenEig to solve
some linear systems involving B.
4) Included header files:
File Contents
----------- ---------------------------------------------
dcmatrxb.h CompMatrixE, a function that generates
matrix A.
dcmatrxc.h CompMatrixF, a function that generates
matrix B.
ardnsmat.h The ARdsNonSymMatrix class definition.
ardgcomp.h The ARluCompGenEig class definition.
lcompsol.h The Solution function.
arcomp.h The "arcomplex" (complex) type definition.
5) ARPACK Authors:
Richard Lehoucq
Kristyn Maschhoff
Danny Sorensen
Chao Yang
Dept. of Computational & Applied Mathematics
Rice University
Houston, Texas
*/
#include "arcomp.h"
#include "dcmatrxb.h"
#include "dcmatrxc.h"
#include "ardnsmat.h"
#include "ardgcomp.h"
#include "lcompsol.h"
int main()
{
// Defining variables;
int n; // Dimension of the problem.
arcomplex<double> rho; // Parameter used to define A.
arcomplex<double> *valA, *valB; // pointers to arrays that store
// the elements of A and B.
// Creating complex matrices A and B.
n = 100;
rho = arcomplex<double>(10.0, 0.0);
CompMatrixB(n, rho, valA);
ARdsNonSymMatrix<arcomplex<double>, double> A(n, valA);
CompMatrixC(n, valB);
ARdsNonSymMatrix<arcomplex<double>, double> B(n, valB);
// Defining what we need: the four eigenvectors with largest magnitude.
ARluCompGenEig<double> dprob(4L, A, B);
// Finding eigenvalues and eigenvectors.
dprob.FindEigenvectors();
// Printing solution.
Solution(A, B, dprob);
} // main.
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