dptsv (l)  Linux Man Pages
dptsv: computes the solution to a real system of linear equations A*X = B, where A is an NbyN symmetric positive definite tridiagonal matrix, and X and B are NbyNRHS matrices
Command to display dptsv
manual in Linux: $ man l dptsv
NAME
DPTSV  computes the solution to a real system of linear equations A*X = B, where A is an NbyN symmetric positive definite tridiagonal matrix, and X and B are NbyNRHS matrices
SYNOPSIS
 SUBROUTINE DPTSV(

N, NRHS, D, E, B, LDB, INFO )

INTEGER
INFO, LDB, N, NRHS

DOUBLE
PRECISION B( LDB, * ), D( * ), E( * )
PURPOSE
DPTSV computes the solution to a real system of linear equations
A*X = B, where A is an NbyN symmetric positive definite tridiagonal
matrix, and X and B are NbyNRHS 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.
ARGUMENTS
 N (input) INTEGER

The order of the matrix A. N >= 0.
 NRHS (input) INTEGER

The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
 D (input/output) DOUBLE PRECISION 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 (input/output) DOUBLE PRECISION array, dimension (N1)

On entry, the (n1) subdiagonal elements of the tridiagonal
matrix A. On exit, the (n1) 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 (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)

On entry, the NbyNRHS right hand side matrix B.
On exit, if INFO = 0, the NbyNRHS solution matrix X.
 LDB (input) INTEGER

The leading dimension of the array B. LDB >= max(1,N).
 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith 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.
Pages related to dptsv
 dptsv (1)  mutual converter between TSV and QDBM Depot database
 dptsv (3)
 dptsvx (l)  uses the factorization A = L*D*L**T to compute the solution to a real system of linear equations A*X = B, where A is an NbyN symmetric positive definite tridiagonal matrix and X and B are NbyNRHS matrices
 dptcon (l)  computes the reciprocal of the condition number (in the 1norm) of a real symmetric positive definite tridiagonal matrix using the factorization A = L*D*L**T or A = U**T*D*U computed by DPTTRF
 dpteqr (l)  computes all eigenvalues and, optionally, eigenvectors of a symmetric positive definite tridiagonal matrix by first factoring the matrix using DPTTRF, and then calling DBDSQR to compute the singular values of the bidiagonal factor
 dptrfs (l)  improves the computed solution to a system of linear equations when the coefficient matrix is symmetric positive definite and tridiagonal, and provides error bounds and backward error estimates for the solution
 dpttrf (l)  computes the L*D*Laq factorization of a real symmetric positive definite tridiagonal matrix A
 dpttrs (l)  solves a tridiagonal system of the form A * X = B using the L*D*Laq factorization of A computed by DPTTRF
 dptts2 (l)  solves a tridiagonal system of the form A * X = B using the L*D*Laq factorization of A computed by DPTTRF