SRC/sptsv.f(3)

NAME
SRC/sptsv.f

SYNOPSIS

  Functions/Subroutines
subroutine sptsv (n, nrhs, d, e, b, ldb, info)
SPTSV computes the solution to system of linear equations A * X = B for PT matrices

Function/Subroutine Documentation

  subroutine sptsv (integer n, integer nrhs, real, dimension( * ) d, real, dimension( * ) e, real, dimension( ldb, * ) b, integer ldb, integer info)

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

Purpose:

    !>
    !> SPTSV computes the solution to a real system of linear equations
    !> A*X = B, where A is an N-by-N symmetric positive definite tridiagonal
    !> matrix, and X and B are N-by-NRHS matrices.
    !>
    !> A is factored as A = L*D*L**T, 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**T.
    !>

    E

    !>          E is REAL 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**T factorization of
    !>          A.  (E can also be regarded as the superdiagonal of the unit
    !>          bidiagonal factor U from the U**T*D*U factorization of A.)
    !>

    B

    !>          B is REAL 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 principal minor of order i
    !>                is not positive, 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.

Definition at line 113 of file sptsv.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.