cpttrs.f man page

cpttrs.f

Synopsis

Functions/Subroutines

subroutine cpttrs (UPLO, N, NRHS, D, E, B, LDB, INFO)
CPTTRS

Function/Subroutine Documentation

subroutine cpttrs (character UPLO, integer N, integer NRHS, real, dimension( * ) D, complex, dimension( * ) E, complex, dimension( ldb, * ) B, integer LDB, integer INFO)

CPTTRS  

Purpose:

 CPTTRS solves a tridiagonal system of the form
    A * X = B
 using the factorization A = U**H*D*U or A = L*D*L**H computed by CPTTRF.
 D is a diagonal matrix specified in the vector D, U (or L) is a unit
 bidiagonal matrix whose superdiagonal (subdiagonal) is specified in
 the vector E, and X and B are N by NRHS matrices.
Parameters:

UPLO

          UPLO is CHARACTER*1
          Specifies the form of the factorization and whether the
          vector E is the superdiagonal of the upper bidiagonal factor
          U or the subdiagonal of the lower bidiagonal factor L.
          = 'U':  A = U**H*D*U, E is the superdiagonal of U
          = 'L':  A = L*D*L**H, E is the subdiagonal of L

N

          N is INTEGER
          The order of the tridiagonal 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.

D

          D is REAL array, dimension (N)
          The n diagonal elements of the diagonal matrix D from the
          factorization A = U**H*D*U or A = L*D*L**H.

E

          E is COMPLEX array, dimension (N-1)
          If UPLO = 'U', the (n-1) superdiagonal elements of the unit
          bidiagonal factor U from the factorization A = U**H*D*U.
          If UPLO = 'L', the (n-1) subdiagonal elements of the unit
          bidiagonal factor L from the factorization A = L*D*L**H.

B

          B is COMPLEX array, dimension (LDB,NRHS)
          On entry, the right hand side vectors B for the system of
          linear equations.
          On exit, 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 = -k, the k-th argument had an illegal value
Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

June 2016

Definition at line 123 of file cpttrs.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Tue Nov 14 2017 Version 3.8.0 LAPACK