eigval_config_type Derived Type

  type, extends(abstract_config_type) :: eigval_config_type
     ! namelist : eigval_knobs
     ! indexed : false
     !> Determines which operator SLEPc is finding eigenvalues of.  If
     !> .false. then SLEPc analyses the time advance operator, so
     !> internally works with the eigenvalue `exp(-i*omega*nadv*dt)`.
     !> If .true. then SLEPc analyses a time derivative operator, so
     !> internally works with the eigenvalue `-i*omega`. Note we form
     !> a first order one sided approximation of the time derivative
     !> (e.g. `(g_{n+nadv}-g_{n})/(nadv*code_dt)`) to be analysed.
     logical :: analyse_ddt_operator = .false.
     !> Sets the extraction technique, must be one of:
     !>
     !> - 'default' (use SLEPC default)
     !> - 'slepc_default' (use SLEPC default)
     !> - 'ritz'
     !> - 'harmonic'
     !> - 'harmonic_relative'
     !> - 'harmonic_right'
     !> - 'harmonic_largest'
     !> - 'refined'
     !> - 'refined_harmonic'
     !>
     character(len = 20) :: extraction_option = 'default'
     !> Sets the maximum number of SLEPC iterations used.  If not set
     !> (recommended) then let SLEPC decide what to use (varies with
     !> different options).
     integer :: max_iter = PETSC_DECIDE
     !> The number of eigenmodes to search for. The actual number of
     !> modes found may be larger than this.
     integer :: n_eig = 1
     !> How many GS2 timesteps to take each time SLEPc wants to
     !> advance the distribution function. Useful to separate closely
     !> spaced eigenvalues without changing [[knobs:delt]].
     integer :: nadv = 1
     !> If `true` then we save a set of restart files for each eigenmode
     !> found. These are named as the standard restart file
     !> (i.e. influenced by the restart_file input), but have `eig_<id>`
     !> appended near the end, where `<id>` is an integer representing the
     !> eigenmode id. If `save_distfn` of [[gs2_diagnostics_knobs]] is true
     !> then will also save the distribution function files.
     logical :: save_restarts = .false.
     !> Sets the type of solver to use, must be one of:
     !>
     !> - 'default' (Krylov-Schur)
     !> - 'slepc_default' (Krylov-Schur)
     !> - 'power'
     !> - 'subspace'
     !> - 'arnoldi'
     !> - 'lanczos'
     !> - 'krylov'
     !> - 'GD'
     !> - 'JD'
     !> - 'RQCG'
     !> - 'CISS'
     !> - 'lapack'
     !> - 'arpack'
     !> - 'blzpack'
     !> - 'trlan'
     !> - 'blopex'
     !> - 'primme'
     !> - 'feast'
     !>
     !> Not all solver types are compatible with other eigenvalue options,
     !> some options may not be supported in older SLEPC versions and some
     !> may require certain flags to be set when SLEPC is compiled.
     character(len = 20) :: solver_option = 'default'
     !> Imaginary part of the eigenvalue target. Often beneficial to
     !> set this fairly large (e.g. 10) when looking for unstable
     !> modes. Used with the `target_*` [[eigval_knobs:which_option]]
     !> mode.
     real :: targ_im = 0.5
     !> Real part of the eigenvalue target. Often beneficial to set
     !> this fairly small (e.g. ~0). Used with the `target_*`
     !> [[eigval_knobs:which_option]] mode.
     real :: targ_re = 0.5
     !> Sets tolerance on SLEPC eigenmode search. Used to determine
     !> when an eigenmode has been found. Note this is the tolerance
     !> based on the SLEPc eigenvalue, which is the time advance
     !> eigenvalue
     !> \(\exp{\left(-i\Omega\textrm{nadv delt}\right)}\)
     !> rather than the GS2 eigenvalue, \(\Omega\).
     real :: tolerance = 1.0d-6
     !> Sets the type of spectral transform to be used. This can help
     !> extract interior eigenvalues. Must be one of
     !>
     !> - 'default' (let SLEPC decide)
     !> - 'slepc_default' (let SLEPC decide)
     !> - 'shell'
     !> - 'shift'
     !> - 'invert'
     !> - 'cayley'
     !> - 'fold'
     !> - 'precond' (not implemented)
     !>
     !> Not all options are available in all versions of the library.
     character(len = 20) :: transform_option = 'default'
     !> If `true` then provide an initial guess for the eigenmode
     !> based on using [[init_g]] routines to initialise `g`. Can be
     !> helpful in accelerating initial phase of eigensolver. Can also
     !> be quite useful with `ginit_option='many'` (etc.)  to start an
     !> eigenvalue search from a previously obtained solution,
     !> allowing both eigenmode refinement and sub-dominant mode
     !> detection.
     logical :: use_ginit = .false.
     !> Sets SLEPC mode of operation (i.e. what sort of eigenvalues it
     !>looks for). Note that this refers to the SLEPc eigenvalue,
     !>i.e. the time advance eigenvalue
     !>\(\exp{\left(-i\Omega\textrm{nadv delt}\right)}\). In other
     !>words one should select `'largest_real'` to search for modes
     !>with the largest growth rate. Must be one of
     !>
     !> - 'default' (equivalent to 'target_magnitude')
     !> - 'slepc_default' (let SLEPC decide)
     !> - 'largest_magnitude'
     !> - 'smallest_magnitude'
     !> - 'largest_real'
     !> - 'smallest_real'
     !> - 'largest_imaginary'
     !> - 'smallest_imaginary'
     !> - 'target_magnitude' (complex eigenvalue magnitude closest to magnitude of target)
     !> - 'target_real'
     !> - 'target_imaginary'
     !> - 'all' (only some solver types, e.g. lapack) -- not supported
     !> - 'user' (will use a user specified function to pick between eigenmodes, note not currently implemented)
     !>
     character(len = 20) :: which_option = 'default'
   contains
     procedure, public :: read => read_eigval_config
     procedure, public :: write => write_eigval_config
     procedure, public :: reset => reset_eigval_config
     procedure, public :: broadcast => broadcast_eigval_config
     procedure, public, nopass :: get_default_name => get_default_name_eigval_config
     procedure, public, nopass :: get_default_requires_index => get_default_requires_index_eigval_config
  end type eigval_config_type