1. Purpose
-------
This directory contains example drivers that call ARPACK subroutines
[c,z]naupd.f and [c,z]neupd.f to solve COMPLEX eigenvalue problems
using regular, inverse or shift-invert modes. These drivers illustrate
how to set various ARPACK parameters to solve different problems in
different modes. They provide a guideline on how to use ARPACK's reverse
communication interface. The user may modify any one of these drivers,
and provide his/her own matrix vector multiplication routine to solve
the problem of his/her own interest.
2. Naming convention
-----------------
The name for each driver has the form 'XndrvN.f', where
X - is 'c' (single precision complex)
or 'z' (double precision complex)
N - is a number between 1 and 4. If
N = 1, the driver solves a STANDARD eigenvalue problem in
REGULAR mode
N = 2, the driver solves a STANDARD eigenvalue problem in
SHIFT-INVERT mode.
N = 3, the driver solves a GENERALIZED eigenvalue problem in
INVERSE mode
N = 4, the driver solves a GENERALIZED eigenvalue problem in
SHIFT-INVERT mode.
For shift-invert modes (N=2,4), the user needs to provide a complex
linear system solver to perform y=inv[A-sigma*B]*x.
3. Usage
-----
To run these drivers, you may use the makefile in this
directory and issue, for example, "make cndrv1". Then
execute using "cndrv1".
