lagts Interface

public interface lagts

LAGTS may be used to solve one of the systems of equations (T - lambdaI)x = y or (T - lambdaI)Tx = y, where T is an n by n tridiagonal matrix, for x, following the factorization of (T - lambdaI) as (T - lambdaI) = PLU , by routine DLAGTF. The choice of equation to be solved is controlled by the argument JOB, and in each case there is an option to perturb zero or very small diagonal elements of U, this option being intended for use in applications such as inverse iteration.


Subroutines

public pure subroutine dlagts(job, n, a, b, c, d, in, y, tol, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: job
integer(kind=ilp), intent(in) :: n
real(kind=dp), intent(in) :: a(*)
real(kind=dp), intent(in) :: b(*)
real(kind=dp), intent(in) :: c(*)
real(kind=dp), intent(in) :: d(*)
integer(kind=ilp), intent(in) :: in(*)
real(kind=dp), intent(inout) :: y(*)
real(kind=dp), intent(inout) :: tol
integer(kind=ilp), intent(out) :: info

public pure subroutine slagts(job, n, a, b, c, d, in, y, tol, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: job
integer(kind=ilp), intent(in) :: n
real(kind=sp), intent(in) :: a(*)
real(kind=sp), intent(in) :: b(*)
real(kind=sp), intent(in) :: c(*)
real(kind=sp), intent(in) :: d(*)
integer(kind=ilp), intent(in) :: in(*)
real(kind=sp), intent(inout) :: y(*)
real(kind=sp), intent(inout) :: tol
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_dlagts()

Arguments

None

public interface stdlib_slagts()

Arguments

None