init_kt_grids_range Subroutine

public subroutine init_kt_grids_range(kt_grids_range_config_in)

FIXME : Add documentation

Arguments

Type IntentOptional Attributes Name
type(kt_grids_range_config_type), intent(in), optional :: kt_grids_range_config_in

Contents

Source Code


Source Code

  subroutine init_kt_grids_range(kt_grids_range_config_in)
    !CMR, 14/10/2013:
    ! New namelist variables nn0, n0_min, n0_max, rhostar_range to set ky grid
    !                                             using toroidal mode numbers.
    ! Toroidal modenumbers are used if n0_min> 0 prescribed in input file.
    use theta_grid, only: drhodpsi
    use file_utils, only: error_unit
    implicit none
    type(kt_grids_range_config_type), intent(in), optional :: kt_grids_range_config_in
    integer :: ierr
    !! Temporary value of n0 as floating point
    real :: n0_tmp
    !! Temporary variable for swapping n0_{min,max}
    integer :: n0_swap

    if (initialized) return
    initialized = .false.

    call read_parameters_range(kt_grids_range_config_in)

    ierr = error_unit()

    !Override kyspacing_option in certain cases
    select case (kyspacingopt_switch)
    case (kyspacingopt_exp)
       if(aky_min.le.0) then
          write(ierr,'("Cannot use kyspacing_option=",A," with aky_min<=0.0 --> setting to",A)') &
               "'exponential'","'linear'"
          kyspacingopt_switch=kyspacingopt_linear
       endif
    end select

    if (n0_min .gt. 0) then
       !CMR if n0_min>0 then override aky inputs and use nn0, n0_min, n0_max to determine aky range

       !Important to only do the following check and fix if nn0 > 0 as the second argument of `mod`
       !must be non-zero. Failing to guard against this can lead to different outcomes with different
       !compilers
       if(nn0 > 1) then

          !If toroidal mode number range would lead to non-integer mode numbers then
          !we adjust the range to try to fix this.
          if(mod(n0_max-n0_min,nn0-1).ne.0) then
             !Give a warning message that we're changing things
             write(ierr,'("Warning: toroidal mode number range setup would lead to non-integer")')
             write(ierr,'("         mode numbers --> Attempting to adjust range slightly.")')

             !n0_max should be n0_min + I*(nn0-1) or n0_min + (I+1)*(nn0-1)
             !where I is int(n0_max-n0_min/(nn0-1)) and we add 1 if the
             !remainder (n0_max-n0_min)/(nn0-1) - I is > 0.5
             !Note it's nn0-1 rather than nn0 as this is number of intervals

             !First calculate the floating step size
             n0_tmp = (n0_max-n0_min*1.0)/(nn0-1)

             !Now construct the new upper limit, int(n0_tmp) = I
             !nint(n0_tmp-int(n0_tmp)) should be either 0 or 1 depending
             !on if the remainder is < or > 0.5
             n0_max = n0_min + (int(n0_tmp)+nint(n0_tmp-int(n0_tmp)))*(nn0-1)

             !Double check it's all OK now, should always be fine but just
             !putting this here in case of logic error or strange cases.
             if(mod(n0_max-n0_min,nn0-1).ne.0) then
                write(ierr,'("Error: Attempt to fix toroidal mode number range failed. Forcing nn0=1")')
                nn0=1
                n0_max = n0_min
             endif
          endif
       end if

       !If n0_min>n0_max swap values
       if(n0_min.gt.n0_max) then
          write(ierr,'("Warning: Swapping max and min n0 values")')
          n0_swap = n0_min
          n0_min = n0_max
          n0_max = n0_swap
       endif

       !If n0_min == n0_max ensure nn0=1
       if(n0_min.eq.n0_max) then
          if(nn0.ne.1) write(ierr,'("Warning: Forcing nn0=1 as n0_min==n0_max.")')
          nn0 = 1
       endif

       !If there's only one mode then force n0_max=n0_min
       if(nn0 .eq. 1) then
          n0_max = n0_min
       endif

       !Set the upper and lower aky limits
       aky_max=n0_max*drhodpsi*rhostar_range
       aky_min=n0_min*drhodpsi*rhostar_range

       !Set the number of aky values
       naky=nn0
    endif

  end subroutine init_kt_grids_range