dgtts2.f - Man Page

SRC/dgtts2.f

Synopsis

Functions/Subroutines

subroutine dgtts2 (itrans, n, nrhs, dl, d, du, du2, ipiv, b, ldb)
DGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf.

Function/Subroutine Documentation

subroutine dgtts2 (integer itrans, integer n, integer nrhs, double precision, dimension( * ) dl, double precision, dimension( * ) d, double precision, dimension( * ) du, double precision, dimension( * ) du2, integer, dimension( * ) ipiv, double precision, dimension( ldb, * ) b, integer ldb)

DGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf.  

Purpose:

 DGTTS2 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

ITRANS

          ITRANS is INTEGER
          Specifies the form of the system of equations.
          = 0:  A * X = B  (No transpose)
          = 1:  A**T* X = B  (Transpose)
          = 2:  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).
Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 127 of file dgtts2.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page dgtts2(3) is an alias of dgtts2.f(3).

Tue Nov 28 2023 12:08:41 Version 3.12.0 LAPACK