HP UX Performance Tools 477

Block diagonal format triangular solve			SBDISM/DBDISM/CBDISM/ZBDISM
Name	SBDISM/DBDISM/CBDISM/ZBDISM
	Block diagonal format triangular solve
Purpose	Block diagonal format triangular solve. Given a scalar α, an upper- or
	lower-triangular sparse matrix A, and a m-by-nmatrix B with m=mb x lb, these
	subprograms compute either of the matrix solutions αA–1B, or αDA–1B, or
	αA–1DB, where D is a diagonal matrix. The size of A is m-by-m. Optionally, A–1
	may be replaced by A–T, or by A–. Here, A–Tis the transpose-inverse and A–
	is the conjugate-transpose-inverse of A. The solution matrix may be stored in
	the result matrix C or optionally may be added to or subtracted from it. This is
	handled in a convenient, but general way by two scalar arguments, α and β,
	which are used as multipliers of the solution matrix and the result matrix.
	Speciﬁcally, these subprograms compute matrix solutions of the form
	C ← αA–1B + βC	C ← αA–TB + βC	C ← αA–*B + βC
	C ← αDA–1B + βC C ← αDA–TB + βC		C ← αDA–*B + βC
	C ← αA–1DB + βC C ← αA–TDB + βC		C ← αA–*DB + βC
Usage	VECLIB:
	SUBROUTINE	SBDISM
	INTEGER*4	transa, mb, n, unitd, blda, nbdiag, lb, ldb, ldc, lwork
	INTEGER*4	descra(), ibdiag()
	REAL*4	alpha, beta
	REAL*4	val(), b(ldb,), c(ldc,), work()

CALL SBDISM (transa, mb, n, unitd, dv, alpha, descra, val, blda, ibdiag, nbdiag, lb, b, ldb, beta, c, ldc, work, lwork)

SUBROUTINE	DBDISM
INTEGER*4	transa, mb, n, unitd, blda, nbdiag, lb, ldb, ldc, lwork
INTEGER*4	descra(), ibdiag()
REAL*8	alpha, beta
REAL*8	val(), b(ldb,), c(ldc,), work()

CALL DBDISM (transa, mb, n, unitd, dv, alpha, descra, val, blda, ibdiag, nbdiag, lb, b, ldb, beta, c, ldc, work, lwork)

SUBROUTINE	CBDISM
INTEGER*4	transa, mb, n, unitd, blda, nbdiag, lb, ldb, ldc, lwork
INTEGER*4	descra(), ibdiag()
COMPLEX*8	alpha, beta
COMPLEX*8	val(), b(ldb,), c(ldc,), work()

CALL CBDISM (transa, mb, n, unitd, dv, alpha, descra, val, blda, ibdiag, nbdiag, lb, b, ldb, beta, c, ldc, work, lwork)

Chapter 4 Sparse BLAS Operations 449