ll_to_xy_proj and xy_to_ll_proj now check for required args and set defaults.

Fixes #61.

src/wrf/g_latlon.py

@@ -8,6 +8,7 @@ from .util import extract_vars, get_id, get_iterable, is_mapping, to_np
 from .py3compat import viewkeys
 from .latlonutils import _lat_varname, _lon_varname, _ll_to_xy, _xy_to_ll
 from .metadecorators import set_latlon_metadata
+from .constants import Constants, ProjectionTypes
 from .config import xarray_enabled
 
 if xarray_enabled():
@@ -388,6 +389,127 @@ def ll_to_xy(wrfin, latitude, longitude, timeidx=0,
                      squeeze, None, _key, as_int, **{})
 
 
+def _set_defaults(projparams):
+    """Check projection parameters and set defaults.
+    
+    Throws an exception if projection parameters required by WPS are not 
+    provided, along with any other parameters required by the map projection
+    transformation routines. 
+    
+    For parameters not used by the projection type, defaults are used so that 
+    the None values don't pass through to fortran downstream.
+    
+    Args:
+    
+        projparams (:obj:`dict`): Projection parameters dictionary.
+        
+    Returns:
+        :obj:`dict`: The projection parameters with default values inserted 
+        where applicable.
+    
+    """
+    _params = dict(projparams)
+    
+    map_proj = _params.get("map_proj")
+    # All projections require these arguments
+    if map_proj is None:
+        raise ValueError("'map_proj' cannot be None")
+    
+    if _params.get("ref_lat") is None:
+        raise ValueError("'ref_lat' cannot be None")
+    
+    if _params.get("ref_lon") is None:
+        raise ValueError("'ref_lon' cannot be None")
+    
+    if _params.get("known_x") is None:
+        raise ValueError("'known_x' cannot be None")
+    
+    if _params.get("known_y") is None:
+        raise ValueError("'known_y' cannot be None")
+    
+    if _params.get("dx") is None:
+        raise ValueError("'dx' cannot be None")
+    
+    # Requires truelat1,stand_lon, truelat2, dx, dy
+    if map_proj == ProjectionTypes.LAMBERT_CONFORMAL:
+        if _params.get("truelat1") is None:
+            raise ValueError("'truelat1' cannot be None")
+        
+        if _params.get("stand_lon") is None:
+            raise ValueError("'stand_lon' cannot be None")
+        
+        if _params.get("truelat2") is None:
+            _params["truelat2"] = _params["truelat1"]
+
+    # Requires truelat1, stand_lon
+    elif map_proj == ProjectionTypes.POLAR_STEREOGRAPHIC:
+        if _params.get("truelat1") is None:
+            raise ValueError("'truelat1' cannot be None")
+        
+        if _params.get("stand_lon") is None:
+            raise ValueError("'stand_lon' cannot be None")
+    
+    # Requires truelat1
+    elif map_proj == ProjectionTypes.MERCATOR:
+        if _params.get("truelat1") is None:
+            raise ValueError("'truelat1' cannot be None")
+        
+        if _params.get("stand_lon") is None:
+            _params["stand_lon"] = 0.0
+    
+    # Requires pole_lat, pole_lon, stand_lon
+    elif map_proj == ProjectionTypes.LAT_LON:        
+        if _params.get("stand_lon") is None:
+            raise ValueError("'stand_lon' cannot be None")
+        
+        if _params.get("dy") is None:
+            raise ValueError("'dy' cannot be None")
+        
+        if _params.get("pole_lat") is None:
+            raise ValueError("'pole_lat' cannot be None")
+            
+        if _params.get("pole_lon") is None:
+            raise ValueError("'pole_lon' cannot be None")
+        
+        if _params.get("latinc") is None:
+            _params["latinc"] = ((_params["dy"]*360.0)/2.0 / 
+                                  Constants.PI/Constants.WRF_EARTH_RADIUS)
+            
+        if _params.get("loninc") is None:
+            _params["loninc"] = ((_params["dx"]*360.0)/2.0 / 
+                                 Constants.PI/Constants.WRF_EARTH_RADIUS)
+        
+    else:
+        raise ValueError("invalid 'map_proj' value of {}".format(map_proj))
+    
+    # Set these to defaults if not used so that the Fortran routines
+    # don't crash
+    if _params.get("truelat1") is None:
+        _params["truelat1"] = 0.
+        
+    if _params.get("truelat2") is None:
+        _params["truelat2"] = 0.
+    
+    if _params.get("pole_lat") is None:
+        _params["pole_lat"] = 90.0
+        
+    if _params.get("pole_lon") is None:
+        _params["pole_lon"] = 0.0
+        
+    if _params.get("dx") is None:
+        _params["dx"] = 0.0
+        
+    if _params.get("dy") is None:
+        _params["dy"] = 0.0
+        
+    if _params.get("latinc") is None:
+        _params["latinc"] = 0.
+        
+    if _params.get("loninc") is None:
+        _params["loninc"] = 0.
+    
+    return _params
+
 
 @set_latlon_metadata(xy=True) 
 def ll_to_xy_proj(latitude, longitude, meta=True, squeeze=True, as_int=True,
@@ -435,7 +557,8 @@ def ll_to_xy_proj(latitude, longitude, meta=True, squeeze=True, as_int=True,
         truelat2 (:obj:`float`): True latitude 2.  Optional for 
             map_proj = 1 (defaults to 0 otherwise).
         
-        stand_lon (:obj:`float`): Standard longitude. Required.
+        stand_lon (:obj:`float`): Standard longitude. Required for map_proj = 
+            1, 2, 6 (defaults to 0 otherwise).
         
         ref_lat (:obj:`float`): A reference latitude.  Required. 
         
@@ -454,10 +577,10 @@ def ll_to_xy_proj(latitude, longitude, meta=True, squeeze=True, as_int=True,
             *map_proj* = 6 (defaults to 0 otherwise).
         
         dx (:obj:`float`): The x spacing in meters at the true latitude.  
-            Required for *map_proj* = 1, 2, 3 (defaults to 0 otherwise).
+            Required for all map projections.
         
         dy (:obj:`float`) - The y spacing in meters at the true latitude.  
-            Required for *map_proj* = 1, 2, 3 (defaults to 0 otherwise).
+            Required for *map_proj* = 6 (defaults to 0 otherwise).
         
         latinc (:obj:`float`): Required for *map_proj* = 6. Defined as:
             
@@ -480,12 +603,14 @@ def ll_to_xy_proj(latitude, longitude, meta=True, squeeze=True, as_int=True,
     
     """
     loc = locals()
-    projparams = {name : loc[name] for name in ("map_proj", "truelat1", 
+    _projparams = {name : loc[name] for name in ("map_proj", "truelat1", 
                                             "truelat2", "stand_lon", "ref_lat",
                                             "ref_lon", "pole_lat", "pole_lon",
                                             "known_x", "known_y", "dx", "dy",
                                             "latinc", "loninc")}
     
+    projparams = _set_defaults(_projparams)
+
     return _ll_to_xy(latitude, longitude, None, 0, True, "cat", squeeze, None,
                      None, as_int, **projparams)
 
@@ -600,7 +725,8 @@ def xy_to_ll_proj(x, y, meta=True, squeeze=True, map_proj=None, truelat1=None,
         truelat2 (:obj:`float`): True latitude 2.  Optional for 
             map_proj = 1 (defaults to 0 otherwise).
         
-        stand_lon (:obj:`float`): Standard longitude. Required.
+        stand_lon (:obj:`float`): Standard longitude. Required for map_proj = 
+            1, 2, 6 (defaults to 0 otherwise).
         
         ref_lat (:obj:`float`): A reference latitude.  Required. 
         
@@ -622,7 +748,7 @@ def xy_to_ll_proj(x, y, meta=True, squeeze=True, map_proj=None, truelat1=None,
             Required for *map_proj* = 1, 2, 3 (defaults to 0 otherwise).
         
         dy (:obj:`float`) - The y spacing in meters at the true latitude.  
-            Required for *map_proj* = 1, 2, 3 (defaults to 0 otherwise).
+            Required for *map_proj* = 6 (defaults to 0 otherwise).
         
         latinc (:obj:`float`): Required for *map_proj* = 6. Defined as:
             
@@ -645,11 +771,13 @@ def xy_to_ll_proj(x, y, meta=True, squeeze=True, map_proj=None, truelat1=None,
         be a :class:`numpy.ndarray` object with no metadata.
     """
     loc = locals()
-    projparams = {name : loc[name] for name in ("map_proj", "truelat1", 
+    _projparams = {name : loc[name] for name in ("map_proj", "truelat1", 
                                             "truelat2", "stand_lon", "ref_lat",
                                             "ref_lon", "pole_lat", "pole_lon",
                                             "known_x", "known_y", "dx", "dy",
                                             "latinc", "loninc")}
+    
+    projparams = _set_defaults(_projparams)
     return _xy_to_ll(x, y, None, 0, None, "cat", squeeze, None, None,
                      **projparams)
 

src/wrf/interp.py

@@ -350,10 +350,9 @@ def vertcross(field3d, vert, levels=None, missing=default_fill(np.float64),
 
 
 @set_interp_metadata("line")
-def interpline(field2d, pivot_point=None, 
+def interpline(field2d, wrfin=None, timeidx=0, stagger=None, projection=None,
-               wrfin=None, timeidx=0, stagger=None, projection=None,
                ll_point=None,
-               angle=None, start_point=None,
+               pivot_point=None, angle=None, start_point=None,
                end_point=None, latlon=False, 
                cache=None, meta=True):
     """Return the two-dimensional field interpolated along a line.

src/wrf/latlonutils.py

@@ -233,7 +233,6 @@ def _kwarg_proj_params(**projparams):
     # Sanity checks
     # Required args for all projections
     for name, var in viewitems({"MAP_PROJ" : map_proj, 
-                                "STAND_LON" : stdlon, 
                                 "REF_LAT" : ref_lat, 
                                 "REF_LON" : ref_lon, 
                                 "KNOWN_X" : known_x, 

test/utests.py

@@ -47,7 +47,7 @@ def setUpModule():
             PATTERN,
             outfile)
     
-        print cmd
+        print(cmd)
     
         if not os.path.exists(outfile):
             status = subprocess.call(cmd, shell=True)
@@ -180,7 +180,7 @@ def make_test(varname, dir, pattern, referent, multi=False, pynio=False):
                 absdiff = np.abs(to_np(my_vals) - ref_vals)
                 maxdiff = np.amax(absdiff)
                 print(maxdiff)
-                print np.argwhere(absdiff == maxdiff)
+                print(np.argwhere(absdiff == maxdiff))
                 
                 raise
     
@@ -519,8 +519,10 @@ def make_interp_test(varname, dir, pattern, referent, multi=False,
                                        int(lats.shape[-1]/2)],
                               lon=lons[int(lons.shape[-2]/2), 
                                        int(lons.shape[-1]/2)])
-            l1 = interpline(t2,wrfin,pivot_point=pivot_point,
+
+            l1 = interpline(t2,wrfin=wrfin,pivot_point=pivot_point,
                            angle=90.0)
+            
             l2 = interpline(t2,projection=t2.attrs["projection"], 
                           ll_point=ll_point, 
                           pivot_point=pivot_point, angle=90.)
@@ -902,6 +904,8 @@ def make_latlon_test(testid, dir, pattern, referent, single,
                 ll_proj = xy_to_ll_proj(x_s[0], y_s[0], **projparams)
                 
                 nt.assert_allclose(to_np(ll_proj), to_np(ll))
+                 
+                
             else:
                 ref_vals = refnc.variables["ll1"][:]
                 ll = xy_to_ll(wrfin, x_s, y_s, timeidx=None)