dpbtrs.f (3) Linux Manual Page
dpbtrs.f –
Synopsis
Functions/Subroutines
subroutine dpbtrs (UPLO, N, KD, NRHS, AB, LDAB, B, LDB, INFO)DPBTRS
Function/Subroutine Documentation
subroutine dpbtrs (characterUPLO, integerN, integerKD, integerNRHS, double precision, dimension( ldab, * )AB, integerLDAB, double precision, dimension( ldb, * )B, integerLDB, integerINFO)
DPBTRS Purpose:
DPBTRS solves a system of linear equations A*X = B with a symmetric
positive definite band matrix A using the Cholesky factorization
A = U**T*U or A = L*L**T computed by DPBTRF.
Parameters:
- UPLO
UPLO is CHARACTER*1
N
= ‘U’: Upper triangular factor stored in AB;
= ‘L’: Lower triangular factor stored in AB.N is INTEGER
KD
The order of the matrix A. N >= 0.KD is INTEGER
NRHS
The number of superdiagonals of the matrix A if UPLO = ‘U’,
or the number of subdiagonals if UPLO = ‘L’. KD >= 0.NRHS is INTEGER
AB
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.AB is DOUBLE PRECISION array, dimension (LDAB,N)
LDAB
The triangular factor U or L from the Cholesky factorization
A = U**T*U or A = L*L**T of the band matrix A, stored in the
first KD+1 rows of the array. The j-th column of U or L is
stored in the j-th column of the array AB as follows:
if UPLO =’U’, AB(kd+1+i-j,j) = U(i,j) for max(1,j-kd)<=i<=j;
if UPLO =’L’, AB(1+i-j,j) = L(i,j) for j<=i<=min(n,j+kd).LDAB is INTEGER
B
The leading dimension of the array AB. LDAB >= KD+1.B is DOUBLE PRECISION array, dimension (LDB,NRHS)
LDB
On entry, the right hand side matrix B.
On exit, the solution matrix X.LDB is INTEGER
INFO
The leading dimension of the array B. LDB >= max(1,N).INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
Author:
- Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
- November 2011
Definition at line 122 of file dpbtrs.f.