
dtptrs.f(3) LAPACK dtptrs.f(3)
NAME
dtptrs.f 
SYNOPSIS
Functions/Subroutines
subroutine dtptrs (UPLO, TRANS, DIAG, N, NRHS, AP, B, LDB, INFO)
DTPTRS
Function/Subroutine Documentation
subroutine dtptrs (characterUPLO, characterTRANS, characterDIAG, integerN, integerNRHS, double
precision, dimension( * )AP, double precision, dimension( ldb, * )B, integerLDB,
integerINFO)
DTPTRS
Purpose:
DTPTRS solves a triangular system of the form
A * X = B or A**T * X = B,
where A is a triangular matrix of order N stored in packed format,
and B is an NbyNRHS matrix. A check is made to verify that A is
nonsingular.
Parameters:
UPLO
UPLO is CHARACTER*1
= 'U': A is upper triangular;
= 'L': A is lower triangular.
TRANS
TRANS is CHARACTER*1
Specifies the form of 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
DIAG is CHARACTER*1
= 'N': A is nonunit triangular;
= 'U': A is unit triangular.
N
N is INTEGER
The order of the matrix A. N >= 0.
NRHS
NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
AP
AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
The upper or lower triangular matrix A, packed columnwise in
a linear array. The jth column of A is stored in the array
AP as follows:
if UPLO = 'U', AP(i + (j1)*j/2) = A(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j1)*(2*nj)/2) = A(i,j) for j<=i<=n.
B
B is DOUBLE PRECISION array, dimension (LDB,NRHS)
On entry, the right hand side matrix B.
On exit, if INFO = 0, the solution matrix X.
LDB
LDB is INTEGER
The leading dimension of the array B. LDB >= max(1,N).
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = i, the ith argument had an illegal value
> 0: if INFO = i, the ith diagonal element of A is zero,
indicating that the matrix is singular and the
solutions X have not been computed.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Definition at line 131 of file dtptrs.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dtptrs.f(3) 
