arpack_t Derived Type

type, public :: arpack_t

General type containing the ARPACK configuration.


Components

Type Visibility Attributes Name Initial
integer, private :: mode

mode of the solver
integer, public :: ido

reverse communication flag
character(len=1), private :: bmat

type of the matrix B ("I" = unit matrix, "G" = general matrix)
integer, private :: evpdim

dimension of the eigenvalue problem
character(len=2), private :: which

which eigenvalues to calculate
integer, private :: nev

number of eigenvalues to calculate
real(kind=dp), private :: tolerance

stopping criteria, relative accuracy of Ritz eigenvalues
complex(kind=dp), public, allocatable :: residual(:)

residual vector
integer, private :: ncv

indicates how many Arnoldi vectors are generated each iteration
integer, public :: iparam(11)

integer array containing mode and parameters
integer, private :: lworkl

length of workl array, must be at least 3 * ncv**2 + 5 * ncv
integer, public :: info

info parameter
integer, private :: maxiter

maximum number of iterations

Type-Bound Procedures

procedure, public :: get_bmat

  • private pure function get_bmat(this)

    Getter for kind of B-matrix in eigenvalue problem.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value character(len=1)

procedure, public :: get_evpdim

  • private pure function get_evpdim(this)

    Getter for dimension of eigenvalue problem.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value integer

procedure, public :: get_which

  • private pure function get_which(this)

    Getter for which eigenvalues to return.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value character(len=2)

procedure, public :: get_nev

  • private pure function get_nev(this)

    Getter for number of eigenvalues to calculate.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value integer

procedure, public :: get_tolerance

  • private pure function get_tolerance(this)

    Getter for tolerance (relative accuracy) to indicate eigenvalue convergence.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value real(kind=dp)

procedure, public :: get_ncv

  • private pure function get_ncv(this)

    Getter for number of Arnoldi basis vectors that should be calculated.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value integer

procedure, public :: get_maxiter

  • private pure function get_maxiter(this)

    Getter for maximum number of iterations.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value integer

procedure, public :: get_lworkl

  • private pure function get_lworkl(this)

    Getter for length of workl array, returns 3 * ncv**2 + 5 * ncv

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

    Return Value integer

procedure, public :: parse_znaupd_info

  • private subroutine parse_znaupd_info(this, converged)

    Parses the info parameter that comes out of ARPACK's znaupd method. If info = 0, everything behaved nicely and the reverse communication subroutines exited properly. If info is any other value something went wrong and we handle it accordingly.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    reference to type object
    logical, intent(out) :: converged

    if .true. the reverse communication routines converged, .false. otherwise

procedure, public :: parse_zneupd_info

  • private subroutine parse_zneupd_info(this)

    Parses the info parameter that comes out of ARPACK's zneupd method. If info = 0, the eigenvalues extraction routines exited properly, if info is any other value something went wrong and we handle it accordingly.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    reference to type object

procedure, public :: parse_finished_stats

  • private subroutine parse_finished_stats(this)

    Parses the statistics that come out of ARPACK when the run is finished. Displays the number of OPX and BX operations and the number of re-orthogonalisation steps that were needed.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(in) :: this

    type instance

procedure, public :: destroy

  • private pure subroutine destroy(this)

    Destructor, deallocates variables.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance

procedure, private :: set_mode

  • private subroutine set_mode(this, mode)

    Sets the mode for the solver.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance
    integer, intent(in) :: mode

    solver mode

procedure, private :: set_bmat

  • private subroutine set_bmat(this, bmat)

    Sets the type of B-matrix.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance
    character(len=1), intent(in) :: bmat

    type of B-matrix

procedure, private :: set_which

  • private subroutine set_which(this, which)

    Setter for the "which" argument of ARPACK routines.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance
    character(len=2), intent(in) :: which

    which kind of eigenvalues to calculate

procedure, private :: set_nev

  • private subroutine set_nev(this, nev)

    Setter for number of eigenvalues to calculate.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance
    integer, intent(in) :: nev

    number of eigenvalues to calculate

procedure, private :: set_residual

  • private subroutine set_residual(this, evpdim)

    Setter for the residual vector, allocates and manually initialises the residual (= starting) vector using a uniform distribution on (-1, 1) for both the real and imaginary parts. Relies on the LAPACK routine zlarnv.

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance
    integer, intent(in) :: evpdim

    dimension of the eigenvalue problem

procedure, private :: set_ncv

  • private subroutine set_ncv(this, ncv)

    Setter for ncv, the number of Arnoldi basis vectors to calculate. This should satisfy 1 <= ncv - nev and ncv <= evpdim, with recommended value ncv = 2 * nev (see arpack docs).

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance
    integer, intent(in) :: ncv

    value for ncv

procedure, private :: set_maxiter

  • private subroutine set_maxiter(this, maxiter)

    Sets the maximum number of iterations that ARPACK is allowed to take, defaults to max(100, 10 * k) with k the number of eigenvalues.

    Read more…

    Arguments

    Type IntentOptional Attributes Name
    class(arpack_t), intent(inout) :: this

    type instance
    integer, intent(in) :: maxiter

    maximum number of iterations