+Make h_neglect argument mandatory in 28 routines

  Made the h_neglect argument non-optional to 28 routines, because there is no
way to provide a consistent hard-coded default for a dimensional parameter.  The
routines where this change was made include remapping_core_h, remapping_core_w,
build_reconstructions_1d, P1M_interpolation, P3M_interpolation,
P3M_boundary_extrapolation, PLM_reconstruction, PLM_boundary_extrapolation,
PPM_reconstruction, PPM_limiter_standard, PPM_boundary_extrapolation,
PQM_reconstruction, PQM_limiter, PQM_boundary_extrapolation_v1,
build_hycom1_column, build_rho_column, bound_edge_values,
edge_values_explicit_h4, edge_values_explicit_h4cw, edge_values_implicit_h4,
edge_slopes_implicit_h3, edge_slopes_implicit_h5, edge_values_implicit_h6,
regridding_set_ppolys, build_and_interpolate_grid, remapByProjection,
remapByDeltaZ, and integrateReconOnInterval.

  In those cases that also have an optional h_neglect_edge argument the default
is now set to h_neglect.  Improperly hard-coded dimensional default values for
h_neglect or h_neglect_edge were eliminated in 15 places as a result of this
change, but they were added back in 2 unit testing routines (one of these is
archaic and unused) that do not use exercise dimensional rescaling tests.

  Because these previously optional arguments were already present in all calls
from the dev/gfdl or main branches of the MOM6 code, all answers are bitwise
identical in the regression tests, but this change in interfaces could impact
other code that is not in the main branch of MOM6.

config_src/drivers/timing_tests/time_MOM_remapping.F90

@@ -17,8 +17,9 @@ program time_MOM_remapping
 real, dimension(nschemes) :: tmin ! Shortest time for a call [s]
 real, dimension(nschemes) :: tmax ! Longest time for a call [s]
 real, dimension(:,:), allocatable :: u0, u1 ! Source/target values [arbitrary but same units as each other]
-real, dimension(:,:), allocatable :: h0, h1 ! Source target thicknesses [0..1]
+real, dimension(:,:), allocatable :: h0, h1 ! Source target thicknesses [0..1] [nondim]
 real :: start, finish ! Times [s]
+real :: h_neglect    ! A negligible thickness [nondim]
 real :: h0sum, h1sum ! Totals of h0 and h1 [nondim]
 integer :: ij, k, isamp, iter, ischeme ! Indices and counters
 integer :: seed_size ! Number of integers used by seed
@@ -50,6 +51,7 @@ program time_MOM_remapping
   h0(:,ij) = h0(:,ij) / h0sum
   h1(:,ij) = h1(:,ij) / h1sum
 enddo
+h_neglect = 1.0-30
 
 ! Loop over many samples of timing loop to collect statistics
 tmean(:) = 0.
@@ -63,7 +65,7 @@ program time_MOM_remapping
     call cpu_time(start)
     do iter = 1, nits ! Make many passes to reduce sampling error
       do ij = 1, nij ! Calling nij times to make similar to cost in MOM_ALE()
-        call remapping_core_h(CS, nk, h0(:,ij), u0(:,ij), nk, h1(:,ij), u1(:,ij))
+        call remapping_core_h(CS, nk, h0(:,ij), u0(:,ij), nk, h1(:,ij), u1(:,ij), h_neglect)
       enddo
     enddo
     call cpu_time(finish)

src/ALE/MOM_remapping.F90

@@ -190,12 +190,12 @@ subroutine remapping_core_h(CS, n0, h0, u0, n1, h1, u1, h_neglect, h_neglect_edg
   integer,             intent(in)  :: n1 !< Number of cells on target grid
   real, dimension(n1), intent(in)  :: h1 !< Cell widths on target grid [H]
   real, dimension(n1), intent(out) :: u1 !< Cell averages on target grid [A]
-  real, optional,      intent(in)  :: h_neglect !< A negligibly small width for the
+  real,                intent(in)  :: h_neglect !< A negligibly small width for the
                                          !! purpose of cell reconstructions
                                          !! in the same units as h0 [H]
-  real, optional,      intent(in)  :: h_neglect_edge !< A negligibly small width
-                                         !! for the purpose of edge value
-                                         !! calculations in the same units as h0 [H]
+  real, optional,      intent(in)  :: h_neglect_edge !< A negligibly small width for the purpose
+                                         !! of edge value calculations in the same units as h0 [H].
+                                         !! The default is h_neglect.
   logical, dimension(n0), optional, intent(in) :: PCM_cell !< If present, use PCM remapping for
                                          !! cells in the source grid where this is true.
 
@@ -204,14 +204,13 @@ subroutine remapping_core_h(CS, n0, h0, u0, n1, h1, u1, h_neglect, h_neglect_edg
   real, dimension(n0,2)           :: ppoly_r_S     ! Edge slope of polynomial [A H-1]
   real, dimension(n0,CS%degree+1) :: ppoly_r_coefs ! Coefficients of polynomial reconstructions [A]
   real :: uh_err       ! A bound on the error in the sum of u*h, as estimated by the remapping code [A H]
-  real :: hNeglect, hNeglect_edge ! Negligibly small cell widths in the same units as h0 [H]
+  real :: hNeglect_edge ! Negligibly small cell widths in the same units as h0 [H]
   integer :: iMethod   ! An integer indicating the integration method used
 
-  hNeglect = 1.0e-30 ; if (present(h_neglect)) hNeglect = h_neglect
-  hNeglect_edge = 1.0e-10 ; if (present(h_neglect_edge)) hNeglect_edge = h_neglect_edge
+  hNeglect_edge = h_neglect ; if (present(h_neglect_edge)) hNeglect_edge = h_neglect_edge
 
   call build_reconstructions_1d( CS, n0, h0, u0, ppoly_r_coefs, ppoly_r_E, ppoly_r_S, iMethod, &
-                                 hNeglect, hNeglect_edge, PCM_cell )
+                                 h_neglect, hNeglect_edge, PCM_cell )
 
   if (CS%om4_remap_via_sub_cells) then
 
@@ -244,27 +243,26 @@ subroutine remapping_core_w( CS, n0, h0, u0, n1, dx, u1, h_neglect, h_neglect_ed
   integer,               intent(in)  :: n1 !< Number of cells on target grid
   real, dimension(n1+1), intent(in)  :: dx !< Cell widths on target grid [H]
   real, dimension(n1),   intent(out) :: u1 !< Cell averages on target grid [A]
-  real, optional,        intent(in)  :: h_neglect !< A negligibly small width for the
+  real,                  intent(in)  :: h_neglect !< A negligibly small width for the
                                            !! purpose of cell reconstructions
                                            !! in the same units as h0 [H].
-  real, optional,        intent(in)  :: h_neglect_edge !< A negligibly small width
-                                           !! for the purpose of edge value
-                                           !! calculations in the same units as h0 [H].
+  real, optional,        intent(in)  :: h_neglect_edge !< A negligibly small width for the purpose
+                                           !! of edge value calculations in the same units as h0 [H].
+                                           !! The default is h_neglect.
   ! Local variables
   real, dimension(n0,2)           :: ppoly_r_E     ! Edge value of polynomial [A]
   real, dimension(n0,2)           :: ppoly_r_S     ! Edge slope of polynomial [A H-1]
   real, dimension(n0,CS%degree+1) :: ppoly_r_coefs ! Coefficients of polynomial reconstructions [A]
   real, dimension(n1) :: h1 !< Cell widths on target grid [H]
   real :: uh_err       ! A bound on the error in the sum of u*h, as estimated by the remapping code [A H]
-  real :: hNeglect, hNeglect_edge  ! Negligibly small thicknesses [H]
+  real :: hNeglect_edge  ! Negligibly small thicknesses [H]
   integer :: iMethod   ! An integer indicating the integration method used
   integer :: k
 
-  hNeglect = 1.0e-30 ; if (present(h_neglect)) hNeglect = h_neglect
-  hNeglect_edge = 1.0e-10 ; if (present(h_neglect_edge)) hNeglect_edge = h_neglect_edge
+  hNeglect_edge = h_neglect ; if (present(h_neglect_edge)) hNeglect_edge = h_neglect_edge
 
   call build_reconstructions_1d( CS, n0, h0, u0, ppoly_r_coefs, ppoly_r_E, ppoly_r_S, iMethod,&
-                                  hNeglect, hNeglect_edge )
+                                  h_neglect, hNeglect_edge )
 
   if (CS%check_reconstruction) call check_reconstructions_1d(n0, h0, u0, CS%degree, &
                                    CS%boundary_extrapolation, ppoly_r_coefs, ppoly_r_E)
@@ -300,19 +298,23 @@ subroutine build_reconstructions_1d( CS, n0, h0, u0, ppoly_r_coefs, &
   real, dimension(n0,2), intent(out) :: ppoly_r_E !< Edge value of polynomial [A]
   real, dimension(n0,2), intent(out) :: ppoly_r_S !< Edge slope of polynomial [A H-1]
   integer,               intent(out) :: iMethod !< Integration method
-  real, optional,        intent(in)  :: h_neglect !< A negligibly small width for the
+  real,                  intent(in)  :: h_neglect !< A negligibly small width for the
                                          !! purpose of cell reconstructions
                                          !! in the same units as h0 [H]
-  real, optional,        intent(in)  :: h_neglect_edge !< A negligibly small width
-                                         !! for the purpose of edge value
-                                         !! calculations in the same units as h0 [H]
+  real, optional,        intent(in)  :: h_neglect_edge !< A negligibly small width for the purpose
+                                         !! of edge value calculations in the same units as h0 [H].
+                                         !! The default is h_neglect.
   logical, optional,     intent(in)  :: PCM_cell(n0) !< If present, use PCM remapping for
                                          !! cells from the source grid where this is true.
 
   ! Local variables
+  real :: h_neg_edge  ! A negligibly small width for the purpose of edge value
+                      ! calculations in the same units as h0 [H]
   integer :: local_remapping_scheme
   integer :: k, n
 
+  h_neg_edge = h_neglect ; if (present(h_neglect_edge)) h_neg_edge = h_neglect_edge
+
   ! Reset polynomial
   ppoly_r_E(:,:) = 0.0
   ppoly_r_S(:,:) = 0.0
@@ -349,22 +351,22 @@ subroutine build_reconstructions_1d( CS, n0, h0, u0, ppoly_r_coefs, &
       iMethod = INTEGRATION_PLM
     case ( REMAPPING_PPM_CW )
       ! identical to REMAPPING_PPM_HYBGEN
-      call edge_values_explicit_h4cw( n0, h0, u0, ppoly_r_E, h_neglect_edge )
+      call edge_values_explicit_h4cw( n0, h0, u0, ppoly_r_E, h_neg_edge )
       call PPM_monotonicity(   n0,     u0, ppoly_r_E )
       call PPM_reconstruction( n0, h0, u0, ppoly_r_E, ppoly_r_coefs, h_neglect, answer_date=CS%answer_date )
       if ( CS%boundary_extrapolation ) then
         call PPM_boundary_extrapolation( n0, h0, u0, ppoly_r_E, ppoly_r_coefs, h_neglect )
       endif
       iMethod = INTEGRATION_PPM
     case ( REMAPPING_PPM_H4 )
-      call edge_values_explicit_h4( n0, h0, u0, ppoly_r_E, h_neglect_edge, answer_date=CS%answer_date )
+      call edge_values_explicit_h4( n0, h0, u0, ppoly_r_E, h_neg_edge, answer_date=CS%answer_date )
       call PPM_reconstruction( n0, h0, u0, ppoly_r_E, ppoly_r_coefs, h_neglect, answer_date=CS%answer_date )
       if ( CS%boundary_extrapolation ) then
         call PPM_boundary_extrapolation( n0, h0, u0, ppoly_r_E, ppoly_r_coefs, h_neglect )
       endif
       iMethod = INTEGRATION_PPM
     case ( REMAPPING_PPM_IH4 )
-      call edge_values_implicit_h4( n0, h0, u0, ppoly_r_E, h_neglect_edge, answer_date=CS%answer_date )
+      call edge_values_implicit_h4( n0, h0, u0, ppoly_r_E, h_neg_edge, answer_date=CS%answer_date )
       call PPM_reconstruction( n0, h0, u0, ppoly_r_E, ppoly_r_coefs, h_neglect, answer_date=CS%answer_date )
       if ( CS%boundary_extrapolation ) then
         call PPM_boundary_extrapolation( n0, h0, u0, ppoly_r_E, ppoly_r_coefs, h_neglect )
@@ -383,7 +385,7 @@ subroutine build_reconstructions_1d( CS, n0, h0, u0, ppoly_r_coefs, &
         call PPM_boundary_extrapolation( n0, h0, u0, ppoly_r_E, ppoly_r_coefs, h_neglect )
       iMethod = INTEGRATION_PPM
     case ( REMAPPING_PQM_IH4IH3 )
-      call edge_values_implicit_h4( n0, h0, u0, ppoly_r_E, h_neglect_edge, answer_date=CS%answer_date )
+      call edge_values_implicit_h4( n0, h0, u0, ppoly_r_E, h_neg_edge, answer_date=CS%answer_date )
       call edge_slopes_implicit_h3( n0, h0, u0, ppoly_r_S, h_neglect, answer_date=CS%answer_date )
       call PQM_reconstruction( n0, h0, u0, ppoly_r_E, ppoly_r_S, ppoly_r_coefs, h_neglect, &
                                answer_date=CS%answer_date )
@@ -393,7 +395,7 @@ subroutine build_reconstructions_1d( CS, n0, h0, u0, ppoly_r_coefs, &
       endif
       iMethod = INTEGRATION_PQM
     case ( REMAPPING_PQM_IH6IH5 )
-      call edge_values_implicit_h6( n0, h0, u0, ppoly_r_E, h_neglect_edge, answer_date=CS%answer_date )
+      call edge_values_implicit_h6( n0, h0, u0, ppoly_r_E, h_neg_edge, answer_date=CS%answer_date )
       call edge_slopes_implicit_h5( n0, h0, u0, ppoly_r_S, h_neglect, answer_date=CS%answer_date )
       call PQM_reconstruction( n0, h0, u0, ppoly_r_E, ppoly_r_S, ppoly_r_coefs, h_neglect, &
                                answer_date=CS%answer_date )
@@ -1615,21 +1617,17 @@ logical function remapping_unit_tests(verbose)
   real :: u02_err ! Error in remaping [A]
   integer, allocatable, dimension(:) :: isrc_start, isrc_end, isrc_max, itgt_start, itgt_end, isub_src ! Indices
   integer :: answer_date  ! The vintage of the expressions to test
-  real, parameter :: hNeglect_dflt = 1.0e-30 ! A thickness [H ~> m or kg m-2] that can be
-                                      ! added to thicknesses in a denominator without
-                                      ! changing the numerical result, except where
-                                      ! a division by zero would otherwise occur.
   real :: err                         ! Errors in the remapped thicknesses [H] or values [A]
   real :: h_neglect, h_neglect_edge   ! Tiny thicknesses used in remapping [H]
   type(testing) :: test ! Unit testing convenience functions
-  integer :: om4
+  integer :: i, om4
   character(len=4) :: om4_tag
 
   call test%set( verbose=verbose ) ! Sets the verbosity flag in test
 
   answer_date = 20190101 ! 20181231
-  h_neglect = hNeglect_dflt
-  h_neglect_edge = hNeglect_dflt ; if (answer_date < 20190101) h_neglect_edge = 1.0e-10
+  h_neglect = 1.0e-30
+  h_neglect_edge = h_neglect ; if (answer_date < 20190101) h_neglect_edge = 1.0e-10
 
   if (verbose) write(test%stdout,*) '  ===== MOM_remapping: remapping_unit_tests ================='
 

src/ALE/P1M_functions.F90

@@ -31,7 +31,7 @@ subroutine P1M_interpolation( N, h, u, edge_values, ppoly_coef, h_neglect, answe
   real, dimension(:,:), intent(inout) :: edge_values !< Potentially modified edge values [A]
   real, dimension(:,:), intent(inout) :: ppoly_coef !< Potentially modified
                                            !! piecewise polynomial coefficients, mainly [A]
-  real,       optional, intent(in)    :: h_neglect !< A negligibly small width [H]
+  real,                 intent(in)    :: h_neglect !< A negligibly small width [H]
   integer,    optional, intent(in)    :: answer_date  !< The vintage of the expressions to use
 
   ! Local variables