[Dart-dev] [4816] DART/trunk/models/wrf/WRF_DART_utilities/wrf_dart_obs_preprocess.f90 : In 3 places this code converted integer nx, ny into reals

[nancy at ucar.edu]

Revision: 4816
Author:   nancy
Date:     2011-03-24 08:58:51 -0600 (Thu, 24 Mar 2011)
Log Message:
-----------
In 3 places this code converted integer nx,ny into reals
using the dble() intrinsic in order to pass a real value to
a subroutine as an argument.  However if this code is compiled
with r8 redefined to be r4 it screws up the subroutine call
because the caller is passing 8 bytes and the receiving code
is expecting 4 bytes. Garbage ensues. This is a problem because
 wrf/dart is frequently compiled r4.  

This fixed version explicitly declares real(r8) vars
and does an assignment so the conversion happens correctly.
The symptom of the bad code was that observations interior
to the domain incorrectly had errors set to very large 
(possibly random) values.

Modified Paths:
--------------
    DART/trunk/models/wrf/WRF_DART_utilities/wrf_dart_obs_preprocess.f90

-------------- next part --------------
Modified: DART/trunk/models/wrf/WRF_DART_utilities/wrf_dart_obs_preprocess.f90
===================================================================
--- DART/trunk/models/wrf/WRF_DART_utilities/wrf_dart_obs_preprocess.f90	2011-03-23 22:38:42 UTC (rev 4815)
+++ DART/trunk/models/wrf/WRF_DART_utilities/wrf_dart_obs_preprocess.f90	2011-03-24 14:58:51 UTC (rev 4816)
@@ -115,6 +115,8 @@
 integer                 :: io, iunit, fid, var_id, obs_seq_file_id, num_copies, &
                            num_qc, num_obs, max_obs_seq, nx, ny, gday, gsec
 
+real(r8)                :: real_nx, real_ny
+
 logical                 :: file_exist, pre_I_format
 
 type(obs_sequence_type) :: seq_all, seq_rawin, seq_sfc, seq_acars, seq_satwnd, &
@@ -147,6 +149,15 @@
                'main', 'inquire dimension south_north' )
 call nc_check( nf90_close(fid), 'main', 'close wrfinput_d01' )
 
+! several places need a real(r8) version of nx and ny, so set them up
+! here so they're ready to use.  previous versions of this code used
+! the conversions dble(nx) but that doesn't work if you are compiling
+! this code with r8 redefined to be r4.  on some platforms it corrupts
+! the arguments to the function call.  these vars are guarenteed to be
+! the right size for code compiled with reals as either r8 or r4.
+real_nx = nx
+real_ny = ny
+
 !  if obs_seq file exists, read in the data, otherwise, create a blank one.
 inquire(file = trim(adjustl(file_name_input)), exist = file_exist)
 if ( file_exist ) then
@@ -171,7 +182,7 @@
 call create_new_obs_seq(num_copies, num_qc, max_num_obs, seq_other)
 
 !  read input obs_seq file, divide into platforms
-call read_and_parse_input_seq(file_name_input, dble(nx), dble(ny), obs_boundary, &
+call read_and_parse_input_seq(file_name_input, real_nx, real_ny, obs_boundary, &
 include_sig_data, obs_pressure_top, obs_height_top, sfc_elevation_check, &
 sfc_elevation_tol, overwrite_ncep_sfc_qc, overwrite_ncep_satwnd_qc, &
 overwrite_obs_time, anal_time, seq_rawin, seq_sfc, seq_acars, seq_satwnd, & 
@@ -269,7 +280,7 @@
 
 !  increase the observation error along the lateral boundary
 if ( increase_bdy_error ) call increase_obs_err_bdy(seq_all, &
-                              obsdistbdy, maxobsfac, dble(nx), dble(ny))
+                              obsdistbdy, maxobsfac, real_nx, real_ny)
 
 !  write the observation sequence to file
 call write_obs_seq(seq_all, file_name_output)
@@ -353,7 +364,9 @@
             rawinsonde_obs_check, aircraft_obs_check, surface_obs_check, &
             sat_wind_obs_check, first_obs
 real(r8) :: xyz_loc(3), xloc, yloc
+real(r8) :: real_nx, real_ny
 
+
 type(location_type)     :: obs_loc_list(max_obs_seq), obs_loc
 type(obs_def_type)      :: obs_def
 type(obs_sequence_type) :: supp_obs_seq
@@ -363,6 +376,10 @@
 inquire(file = trim(adjustl(filename)), exist = file_exist)
 if ( .not. file_exist )  return
 
+! see comment in main routine about why these are needed
+real_nx = nx
+real_ny = ny
+
 select case (plat_kind)
 
   case (RADIOSONDE_U_WIND_COMPONENT)
@@ -419,8 +436,8 @@
   call get_domain_info(xyz_loc(1),xyz_loc(2),dom_id,xloc,yloc)
 
   !  check if the observation is within the domain
-  if ( ((xloc < (obs_bdy+1.0_r8) .or. xloc > (dble(nx)-obs_bdy-1.0_r8) .or. &
-         yloc < (obs_bdy+1.0_r8) .or. yloc > (dble(ny)-obs_bdy-1.0_r8)) .and. &
+  if ( ((xloc < (obs_bdy+1.0_r8) .or. xloc > (real_nx-obs_bdy-1.0_r8) .or. &
+         yloc < (obs_bdy+1.0_r8) .or. yloc > (real_ny-obs_bdy-1.0_r8)) .and. &
          (dom_id == 1)) .or. dom_id < 1 ) then
 
     prev_obsi = obs_in