Per #2152, add logic to add the coordinates variable attributes to gr…

…idded NetCDF variables that contain both the lat and lon dimensions but not for the lat and lon variables themselves.

met/src/libcode/vx_nc_util/nc_utils.cc

@@ -25,8 +25,6 @@ using namespace netCDF::exceptions;
 
 ////////////////////////////////////////////////////////////////////////
 
-////////////////////////////////////////////////////////////////////////
-
 void patch_nc_name(string *var_name) {
    size_t offset;
 
@@ -3216,6 +3214,26 @@ NcVar add_var(NcFile *nc, const string &var_name, const NcType ncType,
       mlog << Debug(3) << "    nc_utils.add_var() deflate_level: " << deflate_level << "\n";
       var.setCompression(false, true, deflate_level);
    }
+
+   // Check for lat and lon dimensions
+   ConcatString cs;
+   bool has_lat_dim, has_lon_dim;
+   vector<NcDim>::const_iterator itDim;
+   for (itDim = ncDims.begin(), has_lat_dim = has_lon_dim = false;
+        itDim != ncDims.end(); ++itDim) {
+           if (itDim->getName() == "lat") has_lat_dim = true;
+      else if (itDim->getName() == "lon") has_lon_dim = true;
+      if (itDim != ncDims.begin()) cs << " ";
+      cs << itDim->getName();
+   }
+
+   // Add the coordinates variable attribute for variables
+   // with both lat and lon dimensions
+   if (has_lat_dim && var_name != "lat" &&
+       has_lon_dim && var_name != "lon") {
+      add_att(&var, "coordinates", cs.c_str());
+   }
+
    return var;
 }