[Dart-dev] DART/branches Revision: 12908

[dart at ucar.edu]

nancy at ucar.edu
2018-10-22 10:57:23 -0600 (Mon, 22 Oct 2018)
667
change name of variable 'cutoff' to 'vert_localize_dist' to make it
more clear that this distance has already been multiplied by 2. 
it isn't the cutoff anymore; the name was misleading.  note this is 
just a variable name change - nothing in the computation has changed.

also changed the subroutine name v_minus() to v_down() to reflect
that this function returns the new vertical location if you start
at vertical location 'a' and move 'b' units towards the earth surface.
calling it 'minus' was confusing because in all cases except height
you are adding b to a to move lower in the atmosphere.

tldr: only name changes for code clarity; no algorithmic changes.




Modified: DART/branches/recam/models/cam-fv/model_mod.f90
===================================================================
--- DART/branches/recam/models/cam-fv/model_mod.f90	2018-10-18 20:29:03 UTC (rev 12907)
+++ DART/branches/recam/models/cam-fv/model_mod.f90	2018-10-22 16:57:23 UTC (rev 12908)
@@ -3638,7 +3638,7 @@
 real(r8),             intent(out) :: extra_dist
 logical :: above_ramp_start
 
-real(r8) :: cutoff, ramp_start, norm, vert_norm, vert_only_dist
+real(r8) :: vert_localize_dist, ramp_start, norm, vert_norm, vert_only_dist
 real(r8) :: horiz_dist, ramp_dist, ramp_width
 type(location_type) :: this_loc, ramp_start_loc, loc1, loc2
 logical, save :: onetime = .true.
@@ -3650,15 +3650,15 @@
 
 ! FIXME: test this!!!
 ! is it above the ramp end? set damp dist to something
-! large enough to turn off all impacts.  is cutoff enough?
-cutoff = get_maxdist(gc, obs_type)
+! large enough to turn off all impacts.  is vert_localize_dist enough?
+vert_localize_dist = get_maxdist(gc, obs_type)
 if (.false. .and. onetime) then
-   print *, 'cutoff = ', cutoff
+   print *, 'vert_localize_dist = ', vert_localize_dist
    onetime = .false.
 endif
 
 if (v_above(test_value, ramp_end)) then
-   extra_dist = cutoff
+   extra_dist = vert_localize_dist
    above_ramp_start = .true.
    return
 endif
@@ -3671,10 +3671,10 @@
 norm = get_dist(loc1, loc2, obs_type)   ! units: rad/loc units
 vert_norm = 1.0_r8 / norm               ! units now: loc units/rad
 
-ramp_start = v_minus(ramp_end, vert_norm * cutoff)
+ramp_start = v_down(ramp_end, vert_norm * vert_localize_dist)
 
-!print *, 'computing ramp start: ramp_end, vert_norm, cutoff', &
-!                    ramp_start, ramp_end, vert_norm, cutoff
+!print *, 'computing ramp start: ramp_end, vert_norm, vert_localize_dist', &
+!                    ramp_start, ramp_end, vert_norm, vert_localize_dist
 
 if (.not. v_above(test_value, ramp_start)) then
    extra_dist = 0.0_r8
@@ -3698,16 +3698,16 @@
 
 ! we need this to compute what?
 if (vert_only_dist > total_dist) then
- !print *, 'unexpected, vert larger than total:  ', vert_only_dist, total_dist
- !print *, 'obs_type, vert_norm = ', obs_type, vert_norm
- horiz_dist = 0.0_r8
+   !print *, 'unexpected, vert larger than total:  ', vert_only_dist, total_dist
+   !print *, 'obs_type, vert_norm = ', obs_type, vert_norm
+   horiz_dist = 0.0_r8
 else
-horiz_dist = sqrt(total_dist**2 - vert_only_dist**2)
+   horiz_dist = sqrt(total_dist**2 - vert_only_dist**2)
 endif
 
 ramp_dist  = v_difference(test_value, ramp_start)
 ramp_width = v_difference(ramp_end,   ramp_start)
-extra_dist = (ramp_dist / ramp_width) * cutoff
+extra_dist = (ramp_dist / ramp_width) * vert_localize_dist
 
 ! DEBUG - disable for now
 if (.false. .and. above_ramp_start) then
@@ -3744,21 +3744,22 @@
 end function v_above
 
 !--------------------------------------------------------------------
-! returns a minus b, where a is higher, b is lower, and the result is
-! yet lower in the atmosphere.
+! returns new value of moving b distance down in the atmosphere
+! starting at a.  for height, this results in a smaller value
+! but for every other vertical type this results in a larger value.
 ! depends on the vertical_localization_type
 
-pure function v_minus(a, b)
+pure function v_down(a, b)
 real(r8), intent(in) :: a, b
-real(r8) :: v_minus
+real(r8) :: v_down
 
 if (vertical_localization_type == VERTISHEIGHT) then
-   v_minus = (a - b)
+   v_down = (a - b)
 else
-   v_minus = (a + b)
+   v_down = (a + b)
 endif
 
-end function v_minus
+end function v_down
 
 !--------------------------------------------------------------------
 ! returns difference of a and b