NSPCG Quick Reference

Calls to Top Level Routines

CALL DFAULT (IPARM,RPARM)

CALL VFILL (N,U,VAL)

CALL NSPCG ($\langle$  precon $\rangle$,$\langle$  accel $\rangle$, NDIM,MDIM,N,MAXNZ,COEF,JCOEF,P,IP,U,UBAR,RHS,

WKSP,IWKSP,NW,INW,IPARM,RPARM,IER)

Calls to Accelerators in Matrix Format-Free Mode

CGW (SUBA,SUBQL, COEF,JCOEF,WFAC,JWFAC,N,U,UBAR,RHS,WKSP,NW,IPARM,RPARM,IER)

SIW (SUBA,SUBQL,COEF,...)

SORW (SUBA,SUBQ,COEF,...)

SRCGW (SUBA,SUBQL,SUBADP,COEF,...)

SRSIW (SUBA,SUBQL,SUBADP,COEF,...)

BASICW (SUBA,SUBQL,SUBQR,COEF,...)

MEW (SUBA,SUBQL,SUBQR,COEF,...)

CGNRW (SUBA,SUBAT,SUBQL,SUBQLT,SUBQR,SUBQRT,COEF,...)

LSQRW (SUBA,SUBAT,SUBQL,SUBQLT,SUBQR,SUBQRT,COEF,...)

ODIRW (SUBA,SUBQL,SUBQR,COEF,...)

OMINW (SUBA,SUBQL,SUBQR,COEF,...)

ORESW (SUBA,SUBQL,SUBQR,COEF,...)

IOMW (SUBA,SUBQL,SUBQR,COEF,...)

GMRESW (SUBA,SUBQL,SUBQR,COEF,...)

USLQW (SUBA,SUBAT,SUBQL,SUBQLT,SUBQR,SUBQRT,COEF,...)

USQRW (SUBA,SUBAT,SUBQL,SUBQLT,SUBQR,SUBQRT,COEF,...)

LDIRW (SUBA,SUBAT,SUBQL,SUBQLT,SUBQR,SUBQRT,COEF,...)

LMINW (SUBA,SUBAT,SUBQL,SUBQLT,SUBQR,SUBQRT,COEF,...)

LRESW (SUBA,SUBAT,SUBQL,SUBQLT,SUBQR,SUBQRT,COEF,...)

BCGSW (SUBA,SUBQL,SUBQR,COEF,...)

Calls to Matrix Format-Free Operations

CALL SUBA (COEF,JCOEF,WFAC,JWFAC,N,X,Y)

CALL SUBAT (COEF,JCOEF,WFAC,JWFAC,N,X,Y)

CALL SUBQL (COEF,JCOEF,WFAC,JWFAC,N,X,Y)

CALL SUBQR (COEF,JCOEF,WFAC,JWFAC,N,X,Y)

CALL SUBQLT (COEF,JCOEF,WFAC,JWFAC,N,X,Y)

CALL SUBQRT (COEF,JCOEF,WFAC,JWFAC,N,X,Y)

CALL SUBQ (COEF,JCOEF,WFAC,JWFAC,N,U,RHS,UNEW)

CALL COPY (COEF,JCOEF,WFAC,JWFAC,N,X,Y)

CALL SUBADP (COEF,JCOEF,WFAC,JWFAC,N,P,R,PDP,PLDUP)

LOGICAL OMGADP

COMMON / ITCOM5 / OMGADP, OMEGA, ALPHAB, BETAB, FFF, SPECR

Calls to Coloring Routines

CALL REDBLK (NDIM,N,MAXNZ,COEF,JCOEF,P,IP,NSTORE,IWKSP,IER)

CALL COLOR (NXP,NYP,NZP,NX,NY,NZ,PATT,P)

Parameter Definitions

$\langle$  precon $\rangle$	preconditioning routine
$\langle$  accel $\rangle$	acceleration routine
NDIM	row dimension of COEF array
MDIM	column dimension of COEF array
N	order of the linear system
MAXNZ	active column width of COEF array
COEF	matrix nonzero coefficients
JCOEF	auxiliary matrix nonzero information
P	optional permutation vector
IP	inverse permutation vector
U	solution vector
UBAR	optional true solution
RHS	right hand side
WKSP	real workspace
IWKSP	integer workspace
NW	length of WKSP
INW	length of IWKSP

IPARM	integer parameters
RPARM	real parameters
IER	error flag
WFAC	real factorization workspace
JWFAC	integer factorization workspace
X	input vector
Y	output vector
NXP,NYP,NZP	dimensions of pattern
NX,NY,NZ	dimensions of grid
PATT	pattern
P	CG direction vector
R	real workspace length N
PDP	(p,Dp) where A=D-CL-CU
PLDUP	(p,CLD-1CUp).

Preconditioners

RICHi	Richardson's method	(i=1,2,3,4,5)
JACi	Jacobi method	(i=1,2,3,4,5)
LJACi	Line Jacobi method	(i=2,3)
LJACXi	Line Jacobi method (approx. inverse)	(i=2,3)
SORi	Successive Overrelaxation	(i=1,2,3,6,7)
SSORi	Symmetric SOR	(i=1,2,3,6,7)
ICi	Incomplete Cholesky	(i=1,2,3,6)
	(Note: IC7 = BIC7 or BICX7)
MICi	Modified Incomplete Cholesky	(i=1,2,3,6)
	(Note: MIC7 = MBIC7 or MBICX7)
LSPi	Least Squares Polynomial	(i=1,2,3,4,5)
NEUi	Neumann Polynomial	(i=1,2,3,4,5)
LSORi	Line SOR	(i=2,3)
LSSORi	Line SSOR	(i=2,3)
LLSPi	Line Least Squares Polynomial	(i=2,3)
LNEUi	Line Neumann Polynomial	(i=2,3)
BICi	Block Incomplete Cholesky (ver. 1)	(i=2,3,7)
BICXi	Block Incomplete Cholesky (ver. 2)	(i=2,3,7)
MBICi	Modified Block Incomplete Cholesky (ver. 1)	(i=2,3,7)
MBICXi	Modified Block Incomplete Cholesky (ver. 2)	(i=2,3,7)
RSi	Reduced System Method	(i=6,7)

i = 1	primary storage format
= 2	symmetric diagonal storage
= 3	nonsymmetric diagonal storage
= 4	symmetric coordinate storage
= 5	nonsymmetric coordinate storage
= 6	permuted primary storage format
= 7	permuted diagonal storage (symmetric or nonsymmetric)

Stopping Tests Associated with NTEST

$$\begin{array}{ll} (1) & {\displaystyle \frac{\mbox{EMAX}}{\m... ...1}b,Q_L^{-1}b\rangle} \right]^\frac{1}{2}< \zeta } \end{array}$$

IER Error Codes

IER	Meaning
0	No error detected
-1	Nonpositive matrix size N
-2	Insufficient real workspace
-3	Insufficient integer workspace
-4	Nonpositive diagonal element
-5	Nonexistent diagonal element
-6	A is not positive definite
-7	Q is not positive definite
-8	Cannot permute matrix as requested
-9	MDIM is not large enough to allow expansion of matrix
-10	Inadmissible parameter encountered
-11	Incorrect storage mode for block method
-12	Zero pivot encountered in factorization
-13	Breakdown in direction vector calculation
-14	Breakdown in attempt to perform rotation
-15	Breakdown in iterate calculation
-16	Unimplemented combination of parameters
-18	Unable to perform eigenvalue estimation
1	Failure to converge in ITMAX iterations
2	ZETA too small - reset to 500*SRELPR
3	ZBRENT failed to converge in MAXFN iterations (signifies difficulty in eigenvalue estimation)
4	In ZBRENT, f(a) and f(b) have the same sign (signifies difficulty in eigenvalue estimation)
5	Negative pivot encountered in factorization

Defaults for IPARM and RPARM Parameters

Position	Name	Default
IPARM(1)	NTEST	2
IPARM(2)	ITMAX	100
IPARM(3)	LEVEL	0
IPARM(4)	NOUT	6
IPARM(5)	IDGTS	0
IPARM(6)	MAXADP	1
IPARM(7)	MINADP	1
IPARM(8)	IOMGAD	1
IPARM(9)	NS1	5
IPARM(10)	NS2	100000
IPARM(11)	NS3	0
IPARM(12)	NSTORE	2
IPARM(13)	ISCALE	0
IPARM(14)	IPERM	0
IPARM(15)	IFACT	1
IPARM(16)	LVFILL	0
IPARM(17)	LTRUNC	0
IPARM(18)	IPROPA	2
IPARM(19)	KBLSZ	-1
IPARM(20)	NBL2D	-1
IPARM(21)	IFCTV	1
IPARM(22)	IQLR	1
IPARM(23)	ISYMM	2
IPARM(24)	IELIM	0
IPARM(25)	NDEG	1

Position	Name	Default
RPARM(1)	ZETA	10-6
RPARM(2)	EMAX	2.0
RPARM(3)	EMIN	1.0
RPARM(4)	FF	0.75
RPARM(5)	FFF	0.75
RPARM(6)	TIMIT	0.0
RPARM(7)	DIGIT1	0.0
RPARM(8)	DIGIT2	0.0
RPARM(9)	OMEGA	1.0
RPARM(10)	ALPHAB	0.0
RPARM(11)	BETAB	0.25
RPARM(12)	SPECR	0.0
RPARM(13)	TIMFAC	0.0
RPARM(14)	TIMTOT	0.0
RPARM(15)	TOL	$500*\mbox{SRELPR}$
RPARM(16)	AINF	0.0