DTBTRS man page on IRIX

Man page or keyword search:  
man Server   31559 pages
apropos Keyword Search (all sections)
Output format
IRIX logo
[printable version]



DTBTRS(3F)							    DTBTRS(3F)

NAME
     DTBTRS - solve a triangular system of the form   A * X = B or A**T * X =
     B,

SYNOPSIS
     SUBROUTINE DTBTRS( UPLO, TRANS, DIAG, N, KD, NRHS, AB, LDAB, B, LDB, INFO
			)

	 CHARACTER	DIAG, TRANS, UPLO

	 INTEGER	INFO, KD, LDAB, LDB, N, NRHS

	 DOUBLE		PRECISION AB( LDAB, * ), B( LDB, * )

PURPOSE
     DTBTRS solves a triangular system of the form

     where A is a triangular band matrix of order N, and B is an N-by NRHS
     matrix.  A check is made to verify that A is nonsingular.

ARGUMENTS
     UPLO    (input) CHARACTER*1
	     = 'U':  A is upper triangular;
	     = 'L':  A is lower triangular.

     TRANS   (input) CHARACTER*1
	     Specifies the form the system of equations:
	     = 'N':  A * X = B	(No transpose)
	     = 'T':  A**T * X = B  (Transpose)
	     = 'C':  A**H * X = B  (Conjugate transpose = Transpose)

     DIAG    (input) CHARACTER*1
	     = 'N':  A is non-unit triangular;
	     = 'U':  A is unit triangular.

     N	     (input) INTEGER
	     The order of the matrix A.	 N >= 0.

     KD	     (input) INTEGER
	     The number of superdiagonals or subdiagonals of the triangular
	     band matrix A.  KD >= 0.

     NRHS    (input) INTEGER
	     The number of right hand sides, i.e., the number of columns of
	     the matrix B.  NRHS >= 0.

     AB	     (input) DOUBLE PRECISION array, dimension (LDAB,N)
	     The upper or lower triangular band matrix A, stored in the first
	     kd+1 rows of AB.  The j-th column of A is stored in the j-th
	     column of the array AB as follows:	 if UPLO = 'U', AB(kd+1+i-j,j)
	     = A(i,j) for max(1,j-kd)<=i<=j; if UPLO = 'L', AB(1+i-j,j)	   =

									Page 1

DTBTRS(3F)							    DTBTRS(3F)

	     A(i,j) for j<=i<=min(n,j+kd).  If DIAG = 'U', the diagonal
	     elements of A are not referenced and are assumed to be 1.

     LDAB    (input) INTEGER
	     The leading dimension of the array AB.  LDAB >= KD+1.

     B	     (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
	     On entry, the right hand side matrix B.  On exit, if INFO = 0,
	     the solution matrix X.

     LDB     (input) INTEGER
	     The leading dimension of the array B.  LDB >= max(1,N).

     INFO    (output) INTEGER
	     = 0:  successful exit
	     < 0:  if INFO = -i, the i-th argument had an illegal value
	     > 0:  if INFO = i, the i-th diagonal element of A is zero,
	     indicating that the matrix is singular and the solutions X have
	     not been computed.

									Page 2

[top]

List of man pages available for IRIX

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net