                readme for solvers directory
/*D 
    SVIntro -  This is the introduction to the solvers, an easy to
use suite of serial iterative and direct solvers.

 Description:

  These routines are intended to be easy to use, they are built 
on top of tools/iter and tools/sparse.

  In order to allow experimentation with different combinations 
of preconditioners, orderings, and accelerators all the underlying
parameters are setable by the user, they default to hopefully 
reasonable values. Settings which do not affect the present solver
situation, eg. if you set the number of GMRES directions while
using the conjugate gradient method are harmless.

  These routines are for MATRIX base solvers only like LU, incomplete
Choleski preconditioners, etc. NOT for special structures like FFT
and multigrid.

$ -----------------Sample Calling Sequences------------------

$ svctx = SVCreate(SpMat *spmat, SolutionMethod);

$    set various optional parameters here

$  SVSetup(SVctx *svctx);

$   set other various optional parameters here

$    SVSolve(SVctx *svctx, b, x);
$    SVSolveAdd(SVctx *svctx, b, x); 
$    SVSolveTranspose(SVctx *svctx, b, x); 

$  SVDestroy(SVctx *svctx);

$ -------------------------------------------------------------
$                    Present solvers available

$ Direct solvers           : sparse LU factorization    SVLU
$ Iterative Preconditioners: Jacobi                     SVJacobi
$                           SSOR                       SVSSOR
$                           ILU  (incomplete LU)       SVILU
$                           ICC  (incomplete Choleski) SVICC

$ The preconditioners can be used with the following accelerators

$                   Conjugate Gradients ITCG
$                   GMRES               ITGMRES
$                   Transpose free QMR  ITTCQMR
$                   Richardson          ITRICHARDSON
$                   Chebychev           ITCHEBYCHEV

$ The LU factorization can be used with the following orderings

$                  Nested dissection         ORDER_ND
$                  Quotient Minimum Degree   ORDER_QMD
$                  Reverse Cuthill-McGee     ORDER_RCM
D*/
