+Add zero_zeros optional arg to MOM_write_field

  Added the new zero_zeros optional argument to the 10 MOM_write_field routines
in MOM_io and the 6 rescale_comp_data routines in MOM_domain_infra to cause
negative zeros to replaced with ordinary signless zeros before they are written
out to files.  This has no impact at all on answers, but it does help with
comparisons between rotated restart files, in which meaningless differences
between positive and negative zeros were leading to false differences between
files.  All answers are bitwise identical, and all output is equivalent, but
there are new optional arguments to 16 routines covered by 2 publicly visible
interfaces.

config_src/infra/FMS1/MOM_domain_infra.F90

@@ -1259,53 +1259,89 @@ end subroutine redistribute_array_4d
 
 
 !> Rescale the values of a 4-D array in its computational domain by a constant factor
-subroutine rescale_comp_data_4d(domain, array, scale)
+subroutine rescale_comp_data_4d(domain, array, scale, zero_zeros)
   type(MOM_domain_type),    intent(in)    :: domain !< MOM domain from which to extract information
   real, dimension(:,:,:,:), intent(inout) :: array  !< The array which is having the data in its
                                                     !! computational domain rescaled
   real,                     intent(in)    :: scale  !< A scaling factor by which to multiply the
                                                     !! values in the computational domain of array
-  integer :: is, ie, js, je
+  logical,        optional, intent(in)    :: zero_zeros !< If present and true, convert negative zeros
+                                                    !! into ordinary signless zeros.
+  logical :: unsign_zeros ! If true, convert negative zeros into ordinary signless zeros.
+  integer :: is, ie, js, je, i, j, k, m
 
-  if (scale == 1.0) return
+  unsign_zeros = .false. ; if (present(zero_zeros)) unsign_zeros = zero_zeros
+
+  if ((scale == 1.0) .and. (.not.unsign_zeros)) return
 
   call get_simple_array_i_ind(domain, size(array,1), is, ie)
   call get_simple_array_j_ind(domain, size(array,2), js, je)
-  array(is:ie,js:je,:,:) = scale*array(is:ie,js:je,:,:)
+  if (scale /= 1.0) &
+    array(is:ie,js:je,:,:) = scale*array(is:ie,js:je,:,:)
+
+  if (unsign_zeros) then ! Convert negative zeros into zeros
+    do m=1,size(array,4) ; do k=1,size(array,3) ; do j=js,je ; do i=is,ie
+      if (array(i,j,k,m) == 0.0) array(i,j,k,m) = 0.0
+    enddo ; enddo ; enddo ; enddo
+  endif
 
 end subroutine rescale_comp_data_4d
 
 !> Rescale the values of a 3-D array in its computational domain by a constant factor
-subroutine rescale_comp_data_3d(domain, array, scale)
+subroutine rescale_comp_data_3d(domain, array, scale, zero_zeros)
   type(MOM_domain_type),  intent(in)    :: domain !< MOM domain from which to extract information
   real, dimension(:,:,:), intent(inout) :: array  !< The array which is having the data in its
                                                   !! computational domain rescaled
   real,                   intent(in)    :: scale  !< A scaling factor by which to multiply the
                                                   !! values in the computational domain of array
-  integer :: is, ie, js, je
+  logical,      optional, intent(in)    :: zero_zeros !< If present and true, convert negative zeros
+                                                  !! into ordinary signless zeros.
+  logical :: unsign_zeros ! If true, convert negative zeros into ordinary signless zeros.
+  integer :: is, ie, js, je, i, j, k
 
-  if (scale == 1.0) return
+  unsign_zeros = .false. ; if (present(zero_zeros)) unsign_zeros = zero_zeros
+
+  if ((scale == 1.0) .and. (.not.unsign_zeros)) return
 
   call get_simple_array_i_ind(domain, size(array,1), is, ie)
   call get_simple_array_j_ind(domain, size(array,2), js, je)
-  array(is:ie,js:je,:) = scale*array(is:ie,js:je,:)
+  if (scale /= 1.0) &
+    array(is:ie,js:je,:) = scale*array(is:ie,js:je,:)
+
+  if (unsign_zeros) then ! Convert negative zeros into zeros
+    do k=1,size(array,3) ; do j=js,je ; do i=is,ie
+      if (array(i,j,k) == 0.0) array(i,j,k) = 0.0
+    enddo ; enddo ; enddo
+  endif
 
 end subroutine rescale_comp_data_3d
 
 !> Rescale the values of a 2-D array in its computational domain by a constant factor
-subroutine rescale_comp_data_2d(domain, array, scale)
+subroutine rescale_comp_data_2d(domain, array, scale, zero_zeros)
   type(MOM_domain_type), intent(in)    :: domain !< MOM domain from which to extract information
   real, dimension(:,:),  intent(inout) :: array  !< The array which is having the data in its
                                                  !! computational domain rescaled
   real,                  intent(in)    :: scale  !< A scaling factor by which to multiply the
                                                  !! values in the computational domain of array
-  integer :: is, ie, js, je
+  logical,      optional, intent(in)   :: zero_zeros !< If present and true, convert negative zeros
+                                                  !! into ordinary signless zeros.
+  logical :: unsign_zeros ! If true, convert negative zeros into ordinary signless zeros.
+  integer :: is, ie, js, je, i, j
+
+  unsign_zeros = .false. ; if (present(zero_zeros)) unsign_zeros = zero_zeros
 
-  if (scale == 1.0) return
+  if ((scale == 1.0) .and. (.not.unsign_zeros)) return
 
   call get_simple_array_i_ind(domain, size(array,1), is, ie)
   call get_simple_array_j_ind(domain, size(array,2), js, je)
-  array(is:ie,js:je) = scale*array(is:ie,js:je)
+  if (scale /= 1.0) &
+    array(is:ie,js:je) = scale*array(is:ie,js:je)
+
+  if (unsign_zeros) then ! Convert negative zeros into zeros
+    do j=js,je ; do i=is,ie
+      if (array(i,j) == 0.0) array(i,j) = 0.0
+    enddo ; enddo
+  endif
 
 end subroutine rescale_comp_data_2d
 

config_src/infra/FMS2/MOM_domain_infra.F90

@@ -1258,53 +1258,89 @@ end subroutine redistribute_array_4d
 
 
 !> Rescale the values of a 4-D array in its computational domain by a constant factor
-subroutine rescale_comp_data_4d(domain, array, scale)
+subroutine rescale_comp_data_4d(domain, array, scale, zero_zeros)
   type(MOM_domain_type),    intent(in)    :: domain !< MOM domain from which to extract information
   real, dimension(:,:,:,:), intent(inout) :: array  !< The array which is having the data in its
                                                     !! computational domain rescaled
   real,                     intent(in)    :: scale  !< A scaling factor by which to multiply the
                                                     !! values in the computational domain of array
-  integer :: is, ie, js, je
+  logical,        optional, intent(in)    :: zero_zeros !< If present and true, convert negative zeros
+                                                    !! into ordinary signless zeros.
+  logical :: unsign_zeros ! If true, convert negative zeros into ordinary signless zeros.
+  integer :: is, ie, js, je, i, j, k, m
 
-  if (scale == 1.0) return
+  unsign_zeros = .false. ; if (present(zero_zeros)) unsign_zeros = zero_zeros
+
+  if ((scale == 1.0) .and. (.not.unsign_zeros)) return
 
   call get_simple_array_i_ind(domain, size(array,1), is, ie)
   call get_simple_array_j_ind(domain, size(array,2), js, je)
-  array(is:ie,js:je,:,:) = scale*array(is:ie,js:je,:,:)
+  if (scale /= 1.0) &
+    array(is:ie,js:je,:,:) = scale*array(is:ie,js:je,:,:)
+
+  if (unsign_zeros) then ! Convert negative zeros into zeros
+    do m=1,size(array,4) ; do k=1,size(array,3) ; do j=js,je ; do i=is,ie
+      if (array(i,j,k,m) == 0.0) array(i,j,k,m) = 0.0
+    enddo ; enddo ; enddo ; enddo
+  endif
 
 end subroutine rescale_comp_data_4d
 
 !> Rescale the values of a 3-D array in its computational domain by a constant factor
-subroutine rescale_comp_data_3d(domain, array, scale)
+subroutine rescale_comp_data_3d(domain, array, scale, zero_zeros)
   type(MOM_domain_type),  intent(in)    :: domain !< MOM domain from which to extract information
   real, dimension(:,:,:), intent(inout) :: array  !< The array which is having the data in its
                                                   !! computational domain rescaled
   real,                   intent(in)    :: scale  !< A scaling factor by which to multiply the
                                                   !! values in the computational domain of array
-  integer :: is, ie, js, je
+  logical,      optional, intent(in)    :: zero_zeros !< If present and true, convert negative zeros
+                                                  !! into ordinary signless zeros.
+  logical :: unsign_zeros ! If true, convert negative zeros into ordinary signless zeros.
+  integer :: is, ie, js, je, i, j, k
 
-  if (scale == 1.0) return
+  unsign_zeros = .false. ; if (present(zero_zeros)) unsign_zeros = zero_zeros
+
+  if ((scale == 1.0) .and. (.not.unsign_zeros)) return
 
   call get_simple_array_i_ind(domain, size(array,1), is, ie)
   call get_simple_array_j_ind(domain, size(array,2), js, je)
-  array(is:ie,js:je,:) = scale*array(is:ie,js:je,:)
+  if (scale /= 1.0) &
+    array(is:ie,js:je,:) = scale*array(is:ie,js:je,:)
+
+  if (unsign_zeros) then ! Convert negative zeros into zeros
+    do k=1,size(array,3) ; do j=js,je ; do i=is,ie
+      if (array(i,j,k) == 0.0) array(i,j,k) = 0.0
+    enddo ; enddo ; enddo
+  endif
 
 end subroutine rescale_comp_data_3d
 
 !> Rescale the values of a 2-D array in its computational domain by a constant factor
-subroutine rescale_comp_data_2d(domain, array, scale)
+subroutine rescale_comp_data_2d(domain, array, scale, zero_zeros)
   type(MOM_domain_type), intent(in)    :: domain !< MOM domain from which to extract information
   real, dimension(:,:),  intent(inout) :: array  !< The array which is having the data in its
                                                  !! computational domain rescaled
   real,                  intent(in)    :: scale  !< A scaling factor by which to multiply the
                                                  !! values in the computational domain of array
-  integer :: is, ie, js, je
+  logical,      optional, intent(in)   :: zero_zeros !< If present and true, convert negative zeros
+                                                  !! into ordinary signless zeros.
+  logical :: unsign_zeros ! If true, convert negative zeros into ordinary signless zeros.
+  integer :: is, ie, js, je, i, j
+
+  unsign_zeros = .false. ; if (present(zero_zeros)) unsign_zeros = zero_zeros
 
-  if (scale == 1.0) return
+  if ((scale == 1.0) .and. (.not.unsign_zeros)) return
 
   call get_simple_array_i_ind(domain, size(array,1), is, ie)
   call get_simple_array_j_ind(domain, size(array,2), js, je)
-  array(is:ie,js:je) = scale*array(is:ie,js:je)
+  if (scale /= 1.0) &
+    array(is:ie,js:je) = scale*array(is:ie,js:je)
+
+  if (unsign_zeros) then ! Convert negative zeros into zeros
+    do j=js,je ; do i=is,ie
+      if (array(i,j) == 0.0) array(i,j) = 0.0
+    enddo ; enddo
+  endif
 
 end subroutine rescale_comp_data_2d