! .. _list-asterosearchcontrols:

   ! ======================
   ! astero_search_controls
   ! ======================

   ! |chi^2| weights
   ! ---------------

   ! chi2_seismo_fraction
   ! ~~~~~~~~~~~~~~~~~~~~

   ! The optimization methods will use and report a total |chi^2| that
   ! is a weighted sum of
   ! seismic and "spectroscopic" (really "non-seismic")
   ! parts. ``chi2_seismo_fraction`` is the weight given to the seismic
   ! part. i.e. the code internally evaluates something like ::

   !   chi2 = chi2_seismo*chi2_seismo_fraction
   !        + chi2_spectro*(1 - chi2_seismo_fraction)

   ! ::

      chi2_seismo_fraction = 0.667d0

   ! Non-seismic ("spectroscopic") observations
   ! ------------------------------------------

   ! ``chi2_spectro`` is a sum of terms for different non-seismic
   ! observables (e.g. Teff, logg, [Fe/H]).  These controls specify what
   ! quantities are added to this |chi^2| and, in some cases, how they
   ! are computed.

   ! Each component is identified by setting its name to either a string
   ! matching a history column or one of the cases defined in ``run_star_extras.f90``.
   ! If target value and uncertainty ``sigma`` are greater than zero, a |chi^2| component
   ! will be computed and output in the sample data.

   ! If ``include_in_chi2_spectro`` is set to ``.true.``, that component will be included
   ! in ``chi2_spectro``.  The old fixed options were equivalent to:

   ! + ``Teff``
   ! + ``log_g``
   ! + ``log_L``
   ! + ``log_R``
   ! + ``M_H`` (was ``FeH``)
   ! + ``surface_Z_div_X``
   ! + ``surface_He``
   ! + ``Rcz``

   ! where ``M_H``, ``surface_Z_div_X``, ``surface_He`` and ``Rcz``
   ! are now implemented in the standard ``run_star_extras.f90``.
   ! The other options fall back to the history columns.

   ! To implement your own constraints, create the appropriate case
   ! in ``set_constraint_value`` in ``run_star_extras.f90``.

   ! The ``age`` option is still treated separately because there are
   ! additional controls that determine how the age target is
   ! approached.

   ! Target values must be set separately for PGstar.  If you want
   ! targets to appear in the ``loggTe`` window, you need to set
   ! the following PGstar controls: ::

   !   loggTe_target_logg
   !   loggTe_target_logg_sigma
   !   loggTe_target_Teff
   !   loggTe_target_Teff_sigma

   ! Similarly, if you want targets to appear in the HR window,
   ! you need to set the following PGstar controls: ::

   !   HR_target_logL
   !   HR_target_logL_sigma
   !   HR_target_Teff
   !   HR_target_Teff_sigma


   ! constraint_name(:)
   ! ~~~~~~~~~~~~~~~~~~
   ! include_constraint_in_chi2_spectro(:)
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! constraint_target(:)
   ! ~~~~~~~~~~~~~~~~~~~~
   ! constraint_sigma(:)
   ! ~~~~~~~~~~~~~~~~~~~
   ! ::

      constraint_name(:) = '' ! change this to whatever you want
      constraint_target(:) = 0
      constraint_sigma(:) = 0
      include_constraint_in_chi2_spectro(:) = .false.


   ! normalize_chi2_spectro
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! If ``.true.``, the total |chi^2| computed for the non-seismic
   ! components (defined above) is divided by the number of components
   ! used to define it.
   ! ::

      normalize_chi2_spectro = .true.


   ! Z_div_X_solar
   ! ~~~~~~~~~~~~~
   ! Convenience parameter leftover from the old interface that
   ! can be used when calculating things relative to solar metallicity.
   ! ::

      Z_div_X_solar = 0.02293d0


   ! include_age_in_chi2_spectro
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! age_target
   ! ~~~~~~~~~~
   ! age_sigma
   ! ~~~~~~~~~
   ! ``age`` is the star's age in years.  When you
   ! ``include_age_in_chi2_spectro``, set ``min_age_for_chi2`` and
   ! ``max_age_for_chi2``, and set ``eval_chi2_at_target_age_only`` to
   ! ``.false.``.  In ``&control``, set ``max_years_for_timestep`` but don't set
   ! ``max_age`` or ``num_adjusted_dt_steps_before_max_age``.
   ! ::

      include_age_in_chi2_spectro = .false.
      age_target = 4.5695d9 ! (see Bahcall, Serenelli, and Basu, 2006)
      age_sigma = 0.0065d9


   ! num_smaller_steps_before_age_target
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      num_smaller_steps_before_age_target = 50 ! only used if > 0

   ! dt_for_smaller_steps_before_age_target
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! This should be much smaller than ``age_sigma``.
   ! ::

      dt_for_smaller_steps_before_age_target = 0.0065d8 ! 1/10 age_sigma


   ! Seismic observations
   ! --------------------

   ! chi2_seismo_delta_nu_fraction
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! chi2_seismo_nu_max_fraction
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! chi2_seismo_r_010_fraction
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! chi2_seismo_r_02_fraction
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~

   ! ``chi2_seismo`` is a weighted combination of the large separation
   ! :math:`\Delta\nu`, the frequency of maximum oscillation power
   ! :math:`\nu_\mathrm{max}`, ratios of frequencies and individual
   ! frequencies.  Specify the weighting of the terms in
   ! ``chi2_seismo`` by setting these controls.  Naturally, all the
   ! fractions must be between zero and one.  If the relevant
   ! fraction is not zero, the corresponding target values and
   ! uncertainties must be set.
   ! ::

      chi2_seismo_delta_nu_fraction = 0d0  ! if > 0 then delta_nu and delta_nu_sigma must be set (see below)
      chi2_seismo_nu_max_fraction = 0d0    ! if > 0 then nu_max and nu_max_sigma must be set (see below)
      chi2_seismo_r_010_fraction = 0d0     ! if > 0, then include r_010 frequency ratios
      chi2_seismo_r_02_fraction = 0d0      ! if > 0, then include r_02 frequency ratios

   ! The fraction for the frequencies is whatever is left. i.e. ::

   !   fraction for frequencies = 1 - (frac_r_010_ratios + frac_r_02_ratios + frac_delta_nu + frac_nu_max)

   ! so if you only want to use individual frequencies in
   ! ``chi2_seismo``, set all four fractions to zero.

   ! normalize_chi2_seismo_frequencies
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! normalize_chi2_seismo_r_010
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! normalize_chi2_seismo_r_02
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! The terms for the frequencies and ratios are sums of terms for
   ! each frequency and ratio.
   ! If you normalize them, they are divided by that number of terms.
   ! ::

      normalize_chi2_seismo_frequencies = .true.
      normalize_chi2_seismo_r_010 = .true.
      normalize_chi2_seismo_r_02 = .true.

   ! trace_chi2_seismo_delta_nu_info
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! trace_chi2_seismo_nu_max_info
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! trace_chi2_seismo_ratios_info
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! trace_chi2_seismo_frequencies_info
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! trace_chi2_spectro_info
   ! ~~~~~~~~~~~~~~~~~~~~~~~
   ! If ``.true.``, output information on that |chi^2| component to the terminal.
   ! ::

      trace_chi2_seismo_delta_nu_info = .false.
      trace_chi2_seismo_nu_max_info = .false.
      trace_chi2_seismo_ratios_info = .false.
      trace_chi2_seismo_frequencies_info = .false.

      trace_chi2_spectro_info = .false. ! if true, output info to terminal


   ! nu_max
   ! ~~~~~~
   ! nu_max_sigma
   ! ~~~~~~~~~~~~
   ! ``nu_max`` is the frequency of maximum oscillation power.  You must set this value if
   ! ``chi2_seismo_nu_max_fraction`` is greater than zero.
   ! ::

      nu_max = -1
      !      ! nu_max is needed when
      !      ! chi2_seismo_nu_max_fraction > 0 or correction_factor > 0 (see below)
      nu_max_sigma = -1


   ! delta_nu
   ! ~~~~~~~~
   ! delta_nu_sigma
   ! ~~~~~~~~~~~~~~
   ! ``delta_nu`` is the large frequency separation (roughly constant
   ! frequency difference between radial modes of increasing order) .
   ! You must set this value if ``chi2_seismo_delta_nu_fraction`` is
   ! greater than zero.
   ! ::

      delta_nu = -1
      delta_nu_sigma = -1

   ! If ``delta_nu`` in the inlist is greater than zero, the
   ! code uses the inlist values for both ``delta_nu`` and
   ! ``delta_nu_sigma``.

   ! If ``delta_nu`` is less than or equal to zero in the inlist, the code estimates it
   ! by a linear fit to the observed radial frequencies and orders, ``l0_obs`` and ``l0_n_obs``.

   ! Along with calculating ``delta_nu``, if ``delta_nu_sigma``
   ! from the inlist is less than zero, then the code also sets
   ! it by using the radial data.  Note that by setting
   ! ``delta_nu_sigma`` to a positive value and ``delta_nu`` to
   ! a negative value, you can have the code get ``delta_nu``
   ! from the given ``l0_obs`` and ``l0_n_obs``, while still
   ! using the ``delta_nu_sigma`` from the inlist.


   ! Mode frequency data
   ! -------------------

   ! nl
   ! ~~
   ! freq_target
   ! ~~~~~~~~~~~
   ! freq_sigma
   ! ~~~~~~~~~~

   ! Data for oscillation modes.  ``nl(el)`` is the number of modes of degree ``el``,
   ! ``freq_target(el,1)`` to ``freq_target(el,nl(el))`` are the
   ! frequencies (in increasing frequency order) and ``freq_sigma(el,1)`` to ``freq_sigma(el,nl(el))`` are
   ! the uncertainties.
   ! ::

      nl(0:3) = 0 ! number of observed modes
      freq_target(0:3,:) = 0 ! frequencies. set e.g. freq_target(0,1) ... freq_target(0,nl(0)) for radial modes
      freq_sigma(0:3,:) = 0 ! freq_sigma(el,i) is uncertainty for freq_target(el,i)


   ! l0_n_obs
   ! ~~~~~~~~
   ! ``l0_n_obs(i)`` is the radial order of ``l0_obs(i)`` for ``i=1, nl0``.
   ! Need to give these if the code is to calculate ``delta_nu`` and ``delta_nu_sigma``.
   ! If you provide ``delta_nu``, then you don't need to set these.
   ! If ``l0_n_obs`` are provided, the Kjeldsen surface correction will use them.
   ! ::

      l0_n_obs(:) = -1


   ! Optimization method
   ! -------------------

   ! eval_chi2_at_target_age_only
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! Set this to ``.true.`` if you only want |chi^2| for a specific age
   ! and no others.  In addition, set ``max_age``, ``max_years_for_timestep``
   ! and ``num_adjusted_dt_steps_before_max_age``.
   ! ::

      eval_chi2_at_target_age_only = .false.


   ! min_age_for_chi2
   ! ~~~~~~~~~~~~~~~~
   ! max_age_for_chi2
   ! ~~~~~~~~~~~~~~~~
   ! Use these if you only want to evaluate chi2 for a given range of ages.
   ! ::

      min_age_for_chi2 = -1 ! (years) only use if > 0
      max_age_for_chi2 = -1 ! (years) only use if > 0


   ! search_type
   ! ~~~~~~~~~~~
   ! This specifies the kind of search to perform, each of which has its
   ! own separate controls further on.  The options are

   ! ``use_first_values``
   !   This option means no search.
   !   Just do a single run using ``first`` values for the parameters.

   ! ``scan_grid``
   !   Evaluates |chi^2| for each parameter combination within the
   !   ``min`` and ``max`` ranges specified below, with the spacing
   !   defined by ``delta``.

   !   For a first rough scan, consider setting ``chi2_seismo_delta_nu_fraction = 1``,
   !   which skips the relatively costly calculations of frequencies
   !   and simply uses ``delta_nu`` along with the non-seismic information.
   !   You can then follow up with medium resolution scans
   !   in smaller regions around candidates from the rough scan
   !   with ``chi2_seismo_delta_nu_fraction = 0`` to include frequencies.

   ! ``simplex``
   !   Search for minimal |chi^2| model using Nelder-Mead simplex algorithm: ::

   !     Nelder, J. A. and Mead, R.
   !     "A Simplex Method for Function Minimization."
   !     Comput. J. 7, 308-313, 1965.

   !   There are versions of this in Numerical Recipes under the name "amoeba",
   !   in Matlab under the name "fminsearch", and in Mathematica as an option for "NMminimize".
   !   Our version has lots of bells and whistles and is, of course, superior to the others. ;)

   ! ``newuoa``
   !   Search for minimal |chi^2| model using Powell's NEWUOA algorithm for
   !   unconstrained minimization without derivatives
   !   by quadratic polynomial approximation. ::

   !       M.J.D. Powell, "Developments of NEWUOA for unconstrained minimization without derivatives",
   !       Department of Applied Mathematics and Theoretical Physics, Cambridge, England, report NA05, 2007.

   ! ``bobyqa``
   !   Search for minimal |chi^2| model using Powell's "Bounded Optimization BY Quadratic Approximation" (BOBYQA) algorithm.
   !   Any location within the bounds is available for consideration. ::

   !       M.J.D. Powell, "The BOBYQA algorithm for bound constrained optimization without derivatives",
   !       Department of Applied Mathematics and Theoretical Physics, Cambridge, England, report NA06, 2009.

   ! ``from_file``
   !   Calculates |chi^2| for the parameter values in a given file.
   !   For each line of the file (after the first, which has column
   !   names), set the parameter values to that of the file for those
   !   parameters with ``vary_param = .true.``.

   ! The two methods from Powell use quadratic interpolation,
   ! either unconstrained (NEWUOA) or bounded (BOBYQA).
   ! The Nelder-Mead simplex method doesn't interpolate;
   ! instead it simply compares values and moves toward lower |chi^2|
   ! and away from higher ones.  In general, you can expect the
   ! Powell methods to converge faster than the simplex if the |chi^2|
   ! terrain is not too "bumpy" (bumps confuse the interpolation).
   ! Since the simplex scheme doesn't do interpolation, bumps
   ! don't cause it as much trouble, so it may be more robust.
   ! If you are just getting started, go with simplex at first.
   ! Try the interpolation methods when you have a very good
   ! candidate and want to look near it for even better results.
   ! ::

      search_type = 'use_first_values'

   ! scan_grid_output_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! Output goes to the following file when ``search_type = 'scan_grid'``.
   ! ::

      scan_grid_output_filename = 'scan_grid_results.data'


   ! restart_scan_grid_from_file
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! If ``.true.``, reads the ``scan_grid_output`` file
   ! and continues from where that stopped.
   ! ::

      restart_scan_grid_from_file = .false.


   ! simplex_itermax
   ! ~~~~~~~~~~~~~~~
   ! Maximum number of iterations of the downhill simplex.
   ! ::

      simplex_itermax = 1000 ! each iteration revises the simplex


   ! simplex_fcn_calls_max
   ! ~~~~~~~~~~~~~~~~~~~~~
   ! Maximum number of function calls for the downhill simplex.
   ! One iteration may use several function calls.
   ! Each "function call" is a stellar evolution track to get a |chi^2|.
   ! ::

      simplex_fcn_calls_max = 10000


   ! simplex_x_atol
   ! ~~~~~~~~~~~~~~
   ! simplex_x_rtol
   ! ~~~~~~~~~~~~~~
   ! Terminate the simplex if the differences between iterations
   ! are less than either of these tolerances.
   ! ::

      simplex_x_atol = 1d-10 ! tolerance for absolute differences
      simplex_x_rtol = 1d-10 ! tolerance for relative differences

   ! If you want the details, here's the snippet of code.
   ! ``simplex(i,j)`` is value of ``i``-th parameter for point ``j``.
   ! ``l`` is the index of the best point.
   ! There are ``n`` parameters and ``n+1`` points. ::

   !     term_val_x = 0
   !     do j=1,n+1 ! check each point
   !        if (j == l) cycle ! l is the best point; so skip it
   !        do i=1,n ! check each coordinate of point j vs point l
   !           term1 = abs(simplex(i,j)-simplex(i,l)) / &
   !              (x_atol + x_rtol*max(abs(simplex(i,j)), abs(simplex(i,l))))
   !           if (term1 > term_val_x) term_val_x = term1
   !        end do
   !     end do
   !     if (term_val_x <= 1d0) exit ! converged


   ! simplex_chi2_tol
   ! ~~~~~~~~~~~~~~~~
   ! Terminate the simplex if the best point has a |chi^2| less than this.
   ! ::

      simplex_chi2_tol = 1d-10 ! tolerance for chi^2


   ! simplex_centroid_weight_power
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! Each iteration starts by doing a reflection
   ! of the worst point through the centroid of the others.
   ! The centroid points are weighted by ``(1/chi^2)**power``.
   ! ``power = 0`` gives the standard unweighted centroid.
   ! ``power > 0`` shifts the reflection towards the better points.
   ! ::

      simplex_centroid_weight_power = 0d0


   ! simplex_enforce_bounds
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! If ``.true.``, points outside the bounds will be rejected without evaluation.
   ! If ``.false.``, the bounds will only be used when creating the initial simplex
   ! and for adaptive random search.
   ! ::

      simplex_enforce_bounds = .false.


   ! simplex_adaptive_random_search
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! This flag controls what is done if the standard options of reflect or contract
   ! fail to produce a improvement in the simplex.
   ! If ``.true.``, test uniform random samples within the bounds until a better point is found.
   ! If ``.false.``, shrink the simplex toward the best point.
   ! ::

      simplex_adaptive_random_search = .false.


   ! simplex_output_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~
   ! Filename for the simplex output.
   ! ::

      simplex_output_filename = 'simplex_results.data'


   ! restart_simplex_from_file
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! If ``.true.``, then reads the output file (``simplex_output_filename``)
   ! and continues from where that stopped
   ! using the best :math:`n+1` results as the initial simplex
   ! (where :math:`n` is the number of parameters).
   ! Note that this restores the best simplex but you may still
   ! see it rerun recent cases if they were not good enough to be
   ! included in the simplex.  We don't restore the information
   ! about those failed attempts, so we need to rerun them.
   ! ::

      restart_simplex_from_file = .false.


   ! simplex_seed
   ! ~~~~~~~~~~~~
   ! Integer seed for random number generation.
   ! ::

      simplex_seed = 1074698122 ! seed for random number generation


   ! simplex_alpha
   ! ~~~~~~~~~~~~~
   ! Coefficients for the reflection step of the downhill simplex algorithm.
   ! ::

      simplex_alpha = 1d0   ! reflect


   ! simplex_beta
   ! ~~~~~~~~~~~~
   ! Coefficients for the expansion step of the downhill simplex algorithm.
   ! ::

      simplex_beta = 2d0   ! expand

   ! simplex_gamma
   ! ~~~~~~~~~~~~~
   ! Coefficients for the contraction step of the downhill simplex algorithm.
   ! ::

      simplex_gamma = 0.5d0  ! contract


   ! simplex_delta
   ! ~~~~~~~~~~~~~
   ! Coefficients for the shrink step of the downhill simplex algorithm.
   ! ::

      simplex_delta = 0.5d0   ! shrink


   ! newuoa_output_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! Filename for the NEWUOA output. ::

      newuoa_output_filename = 'newuoa_results.data'


   ! newuoa_rhoend
   ! ~~~~~~~~~~~~~
   ! This is the tolerance that determines relative accuracy of final values
   ! i.e., NEWUOA stops when results are changing by less than this.
   ! See ``mesa/num/public/num_newuoa`` for details.
   ! ::

      newuoa_rhoend = 1d-6


   ! bobyqa_output_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! Filename for the BOBYQA output.
   ! ::

      bobyqa_output_filename = 'bobyqa_results.data'


   ! bobyqa_rhoend
   ! ~~~~~~~~~~~~~
   ! This is the tolerance that determines relative accuracy of final values
   ! i.e., BOBYQA stops when results are changing by less than this.
   ! See ``mesa/num/public/num_bobyqa`` for details.
   ! ::

      bobyqa_rhoend = 1d-6


   ! filename_for_parameters
   ! ~~~~~~~~~~~~~~~~~~~~~~~
   ! Filename containing parameter values when ``search_type = 'from_file'``.
   ! ::

      filename_for_parameters = 'undefined'


   ! max_num_from_file
   ! ~~~~~~~~~~~~~~~~~
   ! If greater than zero, stop ``from_file`` search after trying this
   ! many lines from the file.
   ! ::

      max_num_from_file = -1 ! if > 0, then stop after doing this many lines from file.


   ! file_column_for_param
   ! ~~~~~~~~~~~~~~~~~~~~~
   ! You need to say which columns in the file hold the various parameters.
   ! For example, if your file starts like the following: ::

   !           chi2         mass        init_Y      init_FeH    alpha       init_f_ov   my_param1   my_param2   my_param3
   !     654   0.81543178   1.35000000  0.27000000  0.21000000  1.76000000  0.01000000  0.00000000  0.00000000  0.00000000

   ! then set the column numbers like this:
   ! ::

      file_column_for_param(1) = 3
      file_column_for_param(2) = 4
      file_column_for_param(3) = 5
      file_column_for_param(4) = 6
      file_column_for_param(5) = 7
      file_column_for_param(6) = 8
      file_column_for_param(7) = 9
      file_column_for_param(8) = 10

   ! Note that if you are not varying one of the parameters, e.g. ``f_ov``,
   ! then you don't need to set the ``file_column`` for that parameter.


   ! from_file_output_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! Filename for the ``from_file`` output.
   ! ::

      from_file_output_filename = 'from_file_results.data'


   ! Parameters
   ! ----------

   ! You can set a large number of parameters (currently up to 100) that will be
   ! searched/optimized for a best-fitting solution.  Specify the
   ! parameters by the name, then either implement your own
   ! parameters in the ``set_param`` subroutine in
   ! ``run_star_extras.f90``, or rely on the default
   ! implementation, which provides the legacy options

   ! * ``initial_mass``
   ! * ``initial_Y``
   ! * ``initial_FeH``
   ! * ``alpha``
   ! * ``f_ov``


   ! param_name
   ! ~~~~~~~~~~
   ! Names for parameters that will searched/optimized.  Empty names ``''``
   ! are ignored.
   ! ::

      param_name(:) = ''


   ! vary_param
   ! ~~~~~~~~~~
   ! If ``.true.``, that parameter will be varied by the search.
   ! If ``.false.``, that parameter will be fixed at the first value
   ! (see ``first_param``).
   ! ::

      vary_param(:) = .false.


   ! first_param
   ! ~~~~~~~~~~~
   ! Initial parameter values for parameters that vary;
   ! fixed values for parameters that don't.
   ! ::

      first_param(:) = 0


   ! min_param
   ! ~~~~~~~~~
   ! max_param
   ! ~~~~~~~~~
   ! Lower and upper bounds for parameter values.
   ! ::

      min_param(:) = 0
      max_param(:) = 0


   ! delta_param
   ! ~~~~~~~~~~~
   ! Grid spacing for parameter values, used when ``search_type = 'scan_grid'``.
   ! ::

      delta_param(:) = 0


   ! Y_depends_on_Z
   ! ~~~~~~~~~~~~~~
   ! Y0
   ! ~~
   ! dYdZ
   ! ~~~~
   ! Legacy controls from the old interface, which is available with
   ! the default ``run_star_extras.f90`` by using the parameter names
   ! ``initial_Y`` and ``initial_FeH``.

   ! If ``Y_depends_on_Z = .false.``, ``Y`` is a parameter like any other and you should set
   ! ``vary_Y``, ``first_Y``, ``min_Y`` and ``max_Y`` (and ``delta_Y`` for a grid).
   ! If ``.true.``, ``Y`` depends on ``Z`` according to ::

   !   Y = Y0 + dYdZ*Z

   ! where ``Y0`` and ``dYdZ`` are set below.
   ! ::

      Y_depends_on_Z = .false.
      Y0 = 0.248d0
      dYdZ = 1.4d0


   ! Y_frac_he3
   ! ~~~~~~~~~~
   ! If using the legacy ``initial_Y`` parameter, this controls the
   ! proportion of the initial helium abundance that's ³He rather than
   ! ⁴He.
   ! ::

      Y_frac_he3 = 1d-4 ! = xhe3/(xhe3 + xhe4); Y = xhe3 + xhe4


   ! f0_ov_div_f_ov
   ! ~~~~~~~~~~~~~~
   ! If using the legacy parameter ``f_ov``, the overshoot ``f0`` is
   ! changed along with overshoot ``f`` according to ::

   !     f0_ov = f0_ov_div_f_ov * f_ov

   ! so this must be set to a positive value if ``f_ov`` is not zero.
   ! ::

      f0_ov_div_f_ov = -1


   ! Parameter limits
   ! ----------------

   ! Calculating mode frequencies is a relatively costly process,
   ! so we don't want to do it for models that are not good candidates.
   ! i.e., we want to filter out the bad candidates using the following
   ! less expensive tests whenever possible.

   ! Note that if none of the models in a run pass these tests,
   ! then you will not get a total |chi^2| result for that run.
   ! That might not matter
   ! but if you are eliminating too many candidates in this way,
   ! the search routines might not get enough valid results to work properly.
   ! So watch what you are doing!  If your search or scan is getting lots of
   ! runs that fail to give |chi^2| results, you'll need to adjust the limits.

   ! min_age_limit
   ! ~~~~~~~~~~~~~
   ! Don't consider models that aren't old enough.
   ! ::

      min_age_limit = 1d6


   ! Lnuc_div_L_limit
   ! ~~~~~~~~~~~~~~~~
   ! Don't consider models with L_nuc/L less than this limit.
   ! This rules out pre-ZAMS models.
   ! ::

      Lnuc_div_L_limit = 0.95


   ! chi2_spectroscopic_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~
   ! Don't consider models with ``chi2_spectro`` above this limit.
   ! ::

      chi2_spectroscopic_limit = 1000


   ! chi2_delta_nu_limit
   ! ~~~~~~~~~~~~~~~~~~~
   ! Don't consider models with ``chi2_delta_nu`` above this limit.
   ! ::

      chi2_delta_nu_limit = 1000


   ! chi2_radial_limit
   ! ~~~~~~~~~~~~~~~~~
   ! We only calculate radial modes if the previous checks pass.

   ! Calculating non-radial modes is much more expensive than radial ones,
   ! so we skip the non-radial calculation if the radial results are poor.

   ! Don't consider models with ``chi2_radial`` above this limit.
   ! ::

      chi2_radial_limit = 100

   ! We only calculate full |chi^2| if the model passes all these
   ! limit checks.


   ! Timestep adjustment
   ! -------------------

   ! We don't want to evaluate more models than we need to but we also
   ! want to make sure that we resolve the optimal |chi^2|.  These
   ! controls adjust the maximum timestep depending on how close we
   ! are to the target values.

   ! If you set the timestep limits too large, you run the risk of
   ! missing good |chi^2| cases.  But if they are very small, you will
   ! spend a lot of runtime calculating lots of frequencies for lots
   ! of models.  There is no standard set of best values for this.
   ! The choice will depend on the stage of evolution and how fast
   ! things are changing in the general region of the models with good
   ! |chi^2| values.  These are just default values: there is no
   ! alternative to trying things and tuning the controls for your
   ! problem.

   ! max_yrs_dt_when_cold
   ! ~~~~~~~~~~~~~~~~~~~~
   ! ::

      max_yrs_dt_when_cold = 1d8 ! when fail Lnuc/L, chi2_spectro, or ch2_delta_nu

   ! max_yrs_dt_when_warm
   ! ~~~~~~~~~~~~~~~~~~~~
   ! ::

      max_yrs_dt_when_warm = 1d7 ! when pass previous but fail chi2_radial; < max_yrs_dt_when_cold

   ! max_yrs_dt_when_hot
   ! ~~~~~~~~~~~~~~~~~~~
   ! ::

      max_yrs_dt_when_hot = 1d6 ! when pass chi2_radial; < max_yrs_dt_when_warm

   ! chi2_limit_for_small_timesteps
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      chi2_limit_for_small_timesteps = -1

   ! max_yrs_dt_chi2_small_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      max_yrs_dt_chi2_small_limit = 3d5 ! < max_yrs_dt_when_hot

   ! chi2_limit_for_smaller_timesteps
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      chi2_limit_for_smaller_timesteps = -1 ! < chi2_limit_for_small_timesteps

   ! max_yrs_dt_chi2_smaller_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      max_yrs_dt_chi2_smaller_limit = 1d5 ! < max_yrs_dt_chi2_small_limit

   ! chi2_limit_for_smallest_timesteps
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      chi2_limit_for_smallest_timesteps = -1 ! < chi2_limit_for_smaller_timesteps

   ! max_yrs_dt_chi2_smallest_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      max_yrs_dt_chi2_smallest_limit = 5d4 ! < max_yrs_dt_chi2_smaller_limit

   ! sigmas_coeff_for_delta_nu_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! sigmas_coeff_for_constraint_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   ! We need a way to decide when to stop an evolution run.
   ! The following limits are used for this.
   ! We don't want to stop too soon, so these limits
   ! are only tested for models that are okay for the ``Lnuc_div_L_limit``.

   ! The limit on each variable ``X`` is ::

   !   X_limit = X_target + X_sigma*sigmas_coeff_for_X_limit

   ! We only use limits where ``sigma_coeff_X`` is not zero.
   ! If ``sigma_coeff`` is positive, we stop when that value is greater than the limit.
   ! If ``sigma_coeff`` is negative, we stop when that value is less than the limit.
   ! Hence, use positive ``sigma_coeff`` for values that are increasing (e.g. ``log_L``)
   ! and negative ``sigma_coeff`` for values that are decreasing
   ! (e.g. ``log_g``, ``Teff``, ``delta_nu``).
   ! ::

      sigmas_coeff_for_delta_nu_limit = 0
      sigmas_coeff_for_constraint_limit(:) = 0


   ! |chi^2| limits
   ! --------------

   ! You can stop the run if |chi^2| is rising.

   ! limit_num_chi2_too_big
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! chi2_relative_increase_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! If any of the following conditions are met in ``limit_num_chi2_too_big`` consecutive models
   ! after a minimum |chi^2| has been found, stop the run for that sample.

   ! + |chi^2| is greater than ``chi2_relative_increase_limit`` times the best |chi^2| for the run.
   ! + ``chi2_spectro``, ``chi2_delta_nu`` or ``chi2_radial`` is greater than its corresponding ``_limit``.
   ! + MESA fails to evaluate |chi^2| (because e.g. it can't match all the modes of a particular degree).

   ! ::

      limit_num_chi2_too_big = 20
      chi2_relative_increase_limit = 2.0


   ! chi2_search_limit1
   ! ~~~~~~~~~~~~~~~~~~
   ! chi2_search_limit2
   ! ~~~~~~~~~~~~~~~~~~
   ! If the best |chi^2| for the run is less than ``chi2_search_limit1``,
   ! stop the run if |chi^2| is greater than ``chi2_search_limit2``.
   ! ::

      chi2_search_limit1 = 3.0
      chi2_search_limit2 = 4.0

   ! If you are doing a search or scanning a grid, you can use previous results
   ! as a guide for when to stop a run


   ! min_num_samples_for_avg
   ! ~~~~~~~~~~~~~~~~~~~~~~~
   ! max_num_samples_for_avg
   ! ~~~~~~~~~~~~~~~~~~~~~~~
   ! avg_age_sigma_limit
   ! ~~~~~~~~~~~~~~~~~~~
   ! avg_model_number_sigma_limit
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! We can stop the run using limits based on the average age of previous samples.
   ! Specifically, use at least ``min_num_samples_for_avg`` and at most
   ! ``max_num_samples_for_avg`` to compute the average age and model number,
   ! then stop the run if the age is greater than the average age or model number
   ! plus ``avg_age_sigma_limit`` or ``avg_model_number_sigma_limit`` times the standard deviation
   ! of the same set of samples.
   ! ::

      min_num_samples_for_avg = 2 ! want at least this many samples to form averages
      max_num_samples_for_avg = 10 ! use this many of the best chi^2 samples for averages
      avg_age_sigma_limit = 10 ! stop if age > avg age + this limit times sigma of avg age
      avg_model_number_sigma_limit = 10 ! ditto for model number


   ! Surface corrections
   ! -------------------
   ! correction_scheme
   ! ~~~~~~~~~~~~~~~~~
   ! The options for the correction scheme are:

   ! + ``'kjeldsen'``, the correction of Kjeldsen et al. (2008);
   ! + ``'power_law'``, a free power law, used as a sanity check in Ball & Gizon (2017);
   ! + ``'cubic'``, the cubic/one-term correction by Ball & Gizon (2014, eqn 3);
   ! + ``'combined'``, the combined/two-term correction by Ball & Gizon (2014, eq 4);
   ! + ``'sonoi'``, the modified Lorentzian by Sonoi et al. (2015, eq 9); or
   ! + ``''``, no corrections.

   ! ::

      correction_scheme = 'kjeldsen'

   ! If you'd like to experiment with your own correction scheme,
   ! you can use the ``other_astero_freq_corr`` hook in ``$MESA_DIR/star``.


   ! surf_coef1_name
   ! ~~~~~~~~~~~~~~~
   ! surf_coef2_name
   ! ~~~~~~~~~~~~~~~
   ! Each surface correction has one or two parameters that are
   ! passed around in the code as ``surf_coef1`` and ``surf_coef2`` and
   ! reported in the output under the control parameters
   ! ``surf_coef1_name`` and ``surf_coef2_name``.
   ! In the various schemes, the surface corrections added to a mode with
   ! frequency :math:`\nu`, normalized inertia :math:`\mathcal{I}`
   ! and relative inertia :math:`Q` are

   !|     kjeldsen         surf_coef1*(ν/νmax)**correction_b / Q (surf_coef2 = correction_r, eq. 6 of K08)
   !|     power_law        surf_coef1*(ν/νmax)**surf_coef2 / Q
   !|     cubic            surf_coef1*(ν/νac)**3 / I             (surf_coef2 is meaningless)
   !|     combined         (surf_coef1*(ν/νac)**3 + surf_coef2/(ν/νac)) / I
   !|     sonoi            surf_coef1*νmax*[1 - 1/(1 + (ν/νmax)**surf_coef2)] / Q

   ! where ``νac`` is the acoustic cutoff frequency, computed by
   ! scaling the solar value of 5mHz in the same way as ``νmax``
   ! (i.e. ``νac = 5mHz * (g/gsun)/sqrt(Teff/Teff_sun)``).
   ! ::

      surf_coef1_name = 'a_div_r'
      surf_coef2_name = 'correction_r'

   ! The default values ``a_div_r`` and ``correction_r`` correspond to the
   ! behaviour in r11701 and before.


   ! correction_factor
   ! ~~~~~~~~~~~~~~~~~
   ! Scale the correction by this fraction.  Set to zero to skip doing corrections
   ! ::

      correction_factor = 0


   ! correction_b
   ! ~~~~~~~~~~~~
   ! Solar-calibrated power law index used in the ``kjeldsen`` surface correction.
   ! The ``kjeldsen`` surface correction uses the observed radial orders of the
   ! radial modes (``l0_n_obs``) if they are provided.
   ! ::

      correction_b = 4.90d0

   ! note: to set nu_max_sun or delta_nu_sun, see star/defaults/controls.defaults

   ! output controls


   ! astero_results_directory
   ! ~~~~~~~~~~~~~~~~~~~~~~~~
   ! Directory in which to save ``astero`` outputs.
   ! If it doesn't exist, it will be created.
   ! ::

      astero_results_directory = 'outputs'


   ! astero_results_dbl_format
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! astero_results_int_format
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! astero_results_txt_format
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~

   ! Formats for writing floats (reals), integers and characters
   ! (strings) to the results file.
   ! ::

      astero_results_dbl_format = '(1pes26.16)'
      astero_results_int_format = '(i26)'
      astero_results_txt_format = '(a26)'


   ! write_best_model_data_for_each_sample
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      write_best_model_data_for_each_sample = .true.


   ! num_digits
   ! ~~~~~~~~~~
   ! Number of digits in sample number (with leading zeros).
   ! ::

      num_digits = 4


   ! sample_results_prefix
   ! ~~~~~~~~~~~~~~~~~~~~~
   ! sample_results_postfix
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! Prefix and postfix for sample results filenames.
   ! ::

      sample_results_prefix = 'sample_'
      sample_results_postfix = '.data'


   ! model_num_digits
   ! ~~~~~~~~~~~~~~~~
   ! Number of digits in model number (with leading zeros).
   ! ::

      model_num_digits = 4


   ! write_fgong_for_each_model
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      write_fgong_for_each_model = .false.

   ! fgong_prefix
   ! ~~~~~~~~~~~~
   ! fgong_postfix
   ! ~~~~~~~~~~~~~
   ! Prefix and postfix for FGONG filenames.
   ! You can include a directory in the prefix if desired
   ! but you must create the directory yourself.
   ! ::

      fgong_prefix = 'fgong_'
      fgong_postfix = '.data'


   ! write_fgong_for_best_model
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      write_fgong_for_best_model = .false.


   ! best_model_fgong_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      best_model_fgong_filename = ''


   ! write_gyre_for_each_model
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      write_gyre_for_each_model = .false.


   ! gyre_prefix
   ! ~~~~~~~~~~~
   ! gyre_postfix
   ! ~~~~~~~~~~~~
   ! Prefix and postfix for GYRE filenames.
   ! You can include a directory in the prefix if desired
   ! but you must create the directory yourself.
   ! ::

      gyre_prefix = 'gyre_'
      gyre_postfix = '.data'


   ! max_num_gyre_points
   ! ~~~~~~~~~~~~~~~~~~~
   ! ::

      max_num_gyre_points = -1 ! only used if > 1

   ! write_gyre_for_best_model
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      write_gyre_for_best_model = .false.


   ! best_model_gyre_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      best_model_gyre_filename = ''


   ! write_profile_for_best_model
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      write_profile_for_best_model = .false.


   ! best_model_profile_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      best_model_profile_filename = ''


   ! save_model_for_best_model
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      save_model_for_best_model = .false.

   ! best_model_save_model_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      best_model_save_model_filename = ''


   ! save_info_for_last_model
   ! ~~~~~~~~~~~~~~~~~~~~~~~~
   ! last_model_save_info_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! If ``save_info_for_last_model = .true.``, treat the final model
   ! as the "best" and save info about final model to
   ! ``last_model_save_info_filename``.
   ! ::

      save_info_for_last_model = .false.
      last_model_save_info_filename = '' ! and save info about final model to this file.


   ! Miscellaneous
   ! -------------

   ! save_next_best_at_higher_frequency
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! save_next_best_at_lower_frequency
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! Save info about next best matches.
   ! ::

      save_next_best_at_higher_frequency = .false.
      save_next_best_at_lower_frequency = .false.


   ! trace_limits
   ! ~~~~~~~~~~~~
   ! If ``.true.``, write info to terminal about status relative to various limits,
   ! e.g. if ``sigmas_coeff_for_Teff_limit`` is set,
   ! ``Teff_limit = Teff_target + Teff_sigma*sigmas_coeff_for_Teff_limit`` and
   ! the run will stop when ``Teff < Teff_limit``.
   ! Trace will write out values of ``Teff`` and ``Teff_limit``.
   ! The same goes for other limits, e.g. ``logg``, ``logL``, ``delta_nu``, etc.
   ! ::

      trace_limits = .false.

   ! save_controls
   ! ~~~~~~~~~~~~~
   ! save_controls_filename
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! If ``save_controls = .true.``, the controls in ``&astero_search_controls``
   ! are dumped to the file ``save_controls_filename``.
   ! If ``save_controls_filename`` is empty, a default filename is used.
   ! ::

      save_controls = .false. ! dumps &astero_search_controls controls to file
      save_controls_filename = '' ! if empty, uses a default name


   ! save_mode_model_number
   ! ~~~~~~~~~~~~~~~~~~~~~~
   ! save_mode_filename
   ! ~~~~~~~~~~~~~~~~~~
   ! el_to_save
   ! ~~~~~~~~~~
   ! order_to_save
   ! ~~~~~~~~~~~~~
   ! Save an eigenfunction.
   ! ::

      save_mode_model_number = 0
      save_mode_filename = ''
      el_to_save = 0
      order_to_save = 0


   ! add_atmosphere
   ! ~~~~~~~~~~~~~~
   ! If ``.true.``, then ``star`` adds the atmosphere structure
   ! before passing the model to ADIPLS or GYRE.
   ! The atmosphere model is determined by the atmosphere boundary
   ! conditions in the ``&controls`` namelist for ``star``.
   ! ::

      add_atmosphere = .false.


   ! keep_surface_point
   ! ~~~~~~~~~~~~~~~~~~
   ! If ``.true.``, keep the ``k=1`` point of model.
   ! ::

      keep_surface_point = .false.


   ! add_center_point
   ! ~~~~~~~~~~~~~~~~
   ! If ``.true.``, add a point at ``r=0``.
   ! ::

      add_center_point = .true.


   ! Oscillation calculation controls
   ! --------------------------------

   ! oscillation_code
   ! ~~~~~~~~~~~~~~~~
   ! Either ``'adipls'`` or ``'gyre'`` (lower case).
   ! ::

      oscillation_code = 'adipls'


   ! trace_time_in_oscillation_code
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! ::

      trace_time_in_oscillation_code = .false.


   ! GYRE controls
   ! -------------
   ! The GYRE controls are read from the ``gyre_input_file``.
   ! Rich offers the following comments on setting them:

   !  I suggest setting freq_min to 0.9*MINVAL(l0_obs),
   !  and freq_max to 1.1*MAXVAL(l0_obs)
   !  (similarly for the other l values).

   !  freq_units should be 'UHZ',
   !  and set grid_type to 'LINEAR'.

   !  For n_freq, I suggest either setting it to 10*(freq_max - freq_min)/dfreq,
   !  where dfreq is the estimated frequency spacing; or, set it to 10*nl0.
   !  The factor 10 is arbitrary, but seems to be a good safety factor.


   ! gyre_input_file
   ! ~~~~~~~~~~~~~~~
   ! ::

      gyre_input_file = 'gyre.in'


   ! gyre_non_ad
   ! ~~~~~~~~~~~
   ! ::

      gyre_non_ad = .false.


   ! ADIPLS controls
   ! ---------------
   ! Some ADIPLS controls are set here.  The rest are set in ``adipls.c.pruned.in``.

   ! ADIPLS looks for frequencies in a given range and with a given "density" of coverage.
   ! For example,
   ! for ``l=0``, the ADIPLS frequency search range is ``nu_lower_factor*l0_obs(1)``
   ! to ``nu_upper_factor*l0_obs(nl0)``
   ! and it uses ``iscan = iscan_factor_l0*nl0`` to determine how fine the scan is over the range.

   ! do_redistribute_mesh
   ! ~~~~~~~~~~~~~~~~~~~~
   ! The number of zones for ADIPLS' remeshing is set in ``redistrb.c.pruned.in``.
   ! If you set this ``.false.``, then the mesh from ``star`` is used directly.
   ! If you set this ``.true.``, then ``astero`` calls ADIPLS's ``redistb`` before doing
   ! the frequency analysis.
   ! ::

      do_redistribute_mesh = .true.


   ! iscan_factor
   ! ~~~~~~~~~~~~
   ! ADIPLS will scan for frequencies at ``iscan_factor(l)`` times the number
   ! of observed ``l`` modes.
   ! ::

      iscan_factor(0) = 15
      iscan_factor(1) = 15
      iscan_factor(2) = 15
      iscan_factor(3) = 15


   ! nu_lower_factor
   ! ~~~~~~~~~~~~~~~
   ! nu_upper_factor
   ! ~~~~~~~~~~~~~~~
   ! The frequency scan range is set from the observed frequencies times these factors.
   ! ::

      nu_lower_factor = 0.8
      nu_upper_factor = 1.2


   ! adipls_irotkr
   ! ~~~~~~~~~~~~~
   ! adipls_nprtkr
   ! ~~~~~~~~~~~~~
   ! adipls_igm1kr
   ! ~~~~~~~~~~~~~
   ! adipls_npgmkr
   ! ~~~~~~~~~~~~~
   ! Miscellaneous ADIPLS parameters for experts.
   ! ::

      adipls_irotkr = 0
      adipls_nprtkr = 0
      adipls_igm1kr = 0
      adipls_npgmkr = 0


   ! Include other inlists
   ! ---------------------

   ! read_extra_astero_search_inlist(1..5)
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! extra_astero_search_inlist_name(1..5)
   ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ! If ``read_extra_astero_search_inlist(i)`` is ``.true.``, then read the namelist
   ! in file ``extra_astero_search_inlist_name(i)``.
   ! ::

      read_extra_astero_search_inlist(:) = .false.
      extra_astero_search_inlist_name(:) = 'undefined'