dgttrs.f man page

dgttrs.f —

Synopsis

Functions/Subroutines

subroutine dgttrs (TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB, INFO)
DGTTRS

Function/Subroutine Documentation

subroutine dgttrs (characterTRANS, integerN, integerNRHS, double precision, dimension( * )DL, double precision, dimension( * )D, double precision, dimension( * )DU, double precision, dimension( * )DU2, integer, dimension( * )IPIV, double precision, dimension( ldb, * )B, integerLDB, integerINFO)

DGTTRS  

Purpose:

 DGTTRS solves one of the systems of equations
    A*X = B  or  A**T*X = B,
 with a tridiagonal matrix A using the LU factorization computed
 by DGTTRF.
Parameters:

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**T* X = B  (Conjugate transpose = Transpose)

N

          N is INTEGER
          The order of the matrix A.

NRHS

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

DL

          DL is DOUBLE PRECISION array, dimension (N-1)
          The (n-1) multipliers that define the matrix L from the
          LU factorization of A.

D

          D is DOUBLE PRECISION array, dimension (N)
          The n diagonal elements of the upper triangular matrix U from
          the LU factorization of A.

DU

          DU is DOUBLE PRECISION array, dimension (N-1)
          The (n-1) elements of the first super-diagonal of U.

DU2

          DU2 is DOUBLE PRECISION array, dimension (N-2)
          The (n-2) elements of the second super-diagonal of U.

IPIV

          IPIV is INTEGER array, dimension (N)
          The pivot indices; for 1 <= i <= n, row i of the matrix was
          interchanged with row IPIV(i).  IPIV(i) will always be either
          i or i+1; IPIV(i) = i indicates a row interchange was not
          required.

B

          B is DOUBLE PRECISION array, dimension (LDB,NRHS)
          On entry, the matrix of right hand side vectors B.
          On exit, B is overwritten by the solution vectors 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 i-th argument had an illegal value
Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 138 of file dgttrs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dgttrs(3) is an alias of dgttrs.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK