cpttrs.f

Section: LAPACK (3)
Updated: Tue Nov 14 2017
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NAME

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.


 

Index

NAME
SYNOPSIS
Functions/Subroutines
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)
Author
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