cptsv.f (3) - Linux Manuals

NAME

cptsv.f -

SYNOPSIS


Functions/Subroutines


subroutine cptsv (N, NRHS, D, E, B, LDB, INFO)
CPTSV computes the solution to system of linear equations A * X = B for PT matrices

Function/Subroutine Documentation

subroutine cptsv (integerN, integerNRHS, real, dimension( * )D, complex, dimension( * )E, complex, dimension( ldb, * )B, integerLDB, integerINFO)

CPTSV computes the solution to system of linear equations A * X = B for PT matrices

Purpose:

 CPTSV computes the solution to a complex system of linear equations
 A*X = B, where A is an N-by-N Hermitian positive definite tridiagonal
 matrix, and X and B are N-by-NRHS matrices.

 A is factored as A = L*D*L**H, and the factored form of A is then
 used to solve the system of equations.


 

Parameters:

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.


D

          D is REAL array, dimension (N)
          On entry, the n diagonal elements of the tridiagonal matrix
          A.  On exit, the n diagonal elements of the diagonal matrix
          D from the factorization A = L*D*L**H.


E

          E is COMPLEX array, dimension (N-1)
          On entry, the (n-1) subdiagonal elements of the tridiagonal
          matrix A.  On exit, the (n-1) subdiagonal elements of the
          unit bidiagonal factor L from the L*D*L**H factorization of
          A.  E can also be regarded as the superdiagonal of the unit
          bidiagonal factor U from the U**H*D*U factorization of A.


B

          B is COMPLEX array, dimension (LDB,NRHS)
          On entry, the N-by-NRHS right hand side matrix B.
          On exit, if INFO = 0, the N-by-NRHS 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 i-th argument had an illegal value
          > 0:  if INFO = i, the leading minor of order i is not
                positive definite, and the solution has not been
                computed.  The factorization has not been completed
                unless i = N.


 

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 116 of file cptsv.f.

Author

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