remap_scrip_io: add global attribute num_neighbors

src/remap_scrip_io.cc

@@ -290,6 +290,9 @@ remap_write_data_scrip(const char *weightsfile, const RemapSwitches &remapSwitch
   auto mapMethod = set_map_method_cstr(remapSwitches, needGridarea);
   put_att_text(ncId, NC_GLOBAL, "map_method", mapMethod);
 
+  if (remapSwitches.mapType == RemapMethod::DISTWGT && remapSwitches.numNeighbors > 1 && remapSwitches.numNeighbors != 4)
+    nce(nc_put_att_int(ncId, NC_GLOBAL, "num_neighbors", NC_INT, 1L, &remapSwitches.numNeighbors));
+
   // Remap order
   if (remapSwitches.mapType == RemapMethod::CONSERV_SCRIP && remapSwitches.submapType == SubmapType::NONE)
     nce(nc_put_att_int(ncId, NC_GLOBAL, "remap_order", NC_INT, 1L, &remapSwitches.remapOrder));
@@ -527,13 +530,22 @@ get_maptype(int ncId)
       if (status == NC_NOERR) remapSwitches.remapOrder = iatt;
     }
   else if (cdo_cmpstrLenRhs(mapMethod, "Bilinear"))
-    remapSwitches.mapType = RemapMethod::BILINEAR;
+    {
+      remapSwitches.mapType = RemapMethod::BILINEAR;
+    }
   else if (cdo_cmpstrLenRhs(mapMethod, "Bicubic"))
-    remapSwitches.mapType = RemapMethod::BICUBIC;
+    {
+      remapSwitches.mapType = RemapMethod::BICUBIC;
+    }
   else if (cdo_cmpstrLenRhs(mapMethod, "Distance"))
     {
+      int numNeighbors = 4;
+      int iatt;
+      int status = nc_get_att_int(ncId, NC_GLOBAL, "num_neighbors", &iatt);
+      if (status == NC_NOERR && iatt > 0) numNeighbors = iatt;
+
       remapSwitches.mapType = RemapMethod::DISTWGT;
-      remapSwitches.numNeighbors = 4;
+      remapSwitches.numNeighbors = numNeighbors;
     }
   else if (cdo_cmpstrLenRhs(mapMethod, "Nearest"))
     {