Improve error messages in uxarray/grid

uxarray/grid/arcs.py

@@ -70,6 +70,8 @@ def point_within_gca(pt_xyz, gca_a_xyz, gca_b_xyz):
         raise ValueError(
             "The input Great Circle Arc spans exactly 180 degrees, which can correspond to multiple planes. "
             "Consider breaking the Great Circle Arc into two smaller arcs."
+            f"\npoint_within_gca(pt_xyz, gca_a_xyz, gca_b_xyz) got gca_a_xyz={gca_a_xyz}, gca_b_xyz={gca_b_xyz}, "
+            f"which are 180 degrees apart. (Was checking pt_xyz={pt_xyz}.)"
         )
 
     # 2. Verify if the point lies on the plane of the GCA
@@ -224,7 +226,8 @@ def extreme_gca_latitude(gca_cart, gca_lonlat, extreme_type):
     """
     # Validate extreme_type
     if (extreme_type != "max") and (extreme_type != "min"):
-        raise ValueError("extreme_type must be either 'max' or 'min'")
+        raise ValueError("Invalid extreme_type. Expected 'max' or 'min'.")
+        # (numba complains about f-strings, so don't put `extreme_type` value in message.)
 
     # Extract the two points
     n1 = gca_cart[0]
@@ -305,7 +308,8 @@ def extreme_gca_z(gca_cart, extreme_type):
 
     # Validate extreme_type
     if (extreme_type != "max") and (extreme_type != "min"):
-        raise ValueError("extreme_type must be either 'max' or 'min'")
+        raise ValueError("Invalid extreme_type. Expected 'max' or 'min'.")
+        # (numba complains about f-strings, so don't put `extreme_type` value in message.)
 
     # Extract the two points
     n1 = gca_cart[0]

uxarray/grid/area.py

@@ -53,7 +53,9 @@ def calculate_face_area(
         dG, dW = get_tri_quadrature_dg(order)
         is_gaussian = False
     else:
-        raise ValueError("Invalid quadrature rule, specify gaussian or triangular")
+        raise ValueError(
+            "Invalid quadrature_rule. Expected 'triangular' or 'gaussian'."
+        )  # (numba complains about f-strings, so don't put actual value in message.)
 
     return _face_area_from_quadrature(
         x, y, z, dG, dW, is_gaussian, latitude_adjusted_area
@@ -253,7 +255,9 @@ def _get_all_face_area_from_coords(
         dG, dW = get_tri_quadrature_dg(order)
         is_gaussian = False
     else:
-        raise ValueError("Invalid quadrature rule, specify gaussian or triangular")
+        raise ValueError(
+            "Invalid quadrature_rule. Expected 'triangular' or 'gaussian'."
+        )  # (numba complains about f-strings, so don't put actual value in message.)
 
     # set initial area of each face to 0
     area = np.zeros(n_face)

uxarray/grid/bounds.py

@@ -416,7 +416,7 @@ def insert_pt_in_latlonbox(old_box, new_pt, is_lon_periodic=True):
     else:
         # Validate longitude point
         if not np.isnan(lon_pt) and (lon_pt < 0.0 or lon_pt > 2.0 * np.pi):
-            raise ValueError("Longitude point out of range")
+            raise ValueError(f"Longitude point out of range (<0 or >2*pi): {lon_pt}")
 
         # Check for pole points
         is_pole_point = False
@@ -466,7 +466,7 @@ def insert_pt_in_latlonbox(old_box, new_pt, is_lon_periodic=True):
                         # Ensure widths are non-negative
                         if (d_width_a < 0.0) or (d_width_b < 0.0):
                             raise AssertionError(
-                                "Logic error in longitude box width calculation"
+                                "Logic error in longitude box width calculation: computed negative width"
                             )
 
                         # Choose the box with the smaller width
@@ -490,8 +490,8 @@ def insert_pt_in_latlonbox(old_box, new_pt, is_lon_periodic=True):
 
                         # Ensure widths are non-negative
                         if (d_width_a < 0.0) or (d_width_b < 0.0):
-                            raise Exception(
-                                "Logic error in longitude box width calculation"
+                            raise AssertionError(
+                                "Logic error in longitude box width calculation: computed negative width"
                             )
 
                         # Choose the box with the smaller width

uxarray/grid/coordinates.py

@@ -773,7 +773,8 @@ def prepare_points(points, normalize):
             x, y, z = _normalize_xyz(x, y, z)
     else:
         raise DimensionError(
-            "Points must be a sequence of length 2 (longitude, latitude) or 3 (x, y, z coordinates)."
+            "Expected len(points) == 2 (for longitude, latitude) or 3 (for x, y, z coordinates); "
+            f"got len(points)={len(points)}, in grid.coordinates.prepare_points"
         )
 
     return np.vstack([x, y, z]).T
@@ -811,7 +812,8 @@ def points_atleast_2d_xyz(points):
         points_xyz = points
     else:
         raise DimensionError(
-            "Points are neither Cartesian (shape N x 3) nor Spherical (shape N x 2)."
+            "Expected points.shape == (N,2) or (N,3) for (lon, lat) or (x, y, z), "
+            f"respectively; got points.shape == {points.shape}."
         )
 
     return points_xyz

uxarray/grid/geometry.py

@@ -447,8 +447,8 @@ def _grid_to_matplotlib_polycollection(
     # Handle unsupported configuration: splitting periodic elements with projection
     if periodic_elements == "split" and projection is not None:
         raise ValueError(
-            "Explicitly projecting lines is not supported. Please pass in your projection "
-            "using the 'transform' parameter"
+            'Must provide `projection` when periodic_elements=="split" '
+            "while attempting to create polycollection, but got projection=None."
         )
 
     # Correct the central longitude and build polygon shells
@@ -717,6 +717,7 @@ def pole_point_inside_polygon(pole, face_edges_xyz, face_edges_lonlat):
 
     if pole != 1 and pole != -1:
         raise ValueError("Pole must be 1 (North) or -1 (South)")
+        # (numba complains about f-strings, so don't put `pole` value in message.)
 
     # Define constants within the function
     pole_point_xyz = np.empty(3, dtype=np.float64)
@@ -838,7 +839,11 @@ def pole_point_inside_polygon(pole, face_edges_xyz, face_edges_lonlat):
         return ((north_intersections + south_intersections) % 2) != 0
 
     else:
-        raise ValueError("Invalid pole point query.")
+        # (location will always be 1, -1, or 0 from _classify_polygon_location,
+        #  so it should always be handled by cases above.)
+        raise AssertionError(
+            "Internal coding/implementation error: invalid `location`."
+        )
 
 
 @njit(cache=True)
@@ -1272,8 +1277,10 @@ def barycentric_coordinates_cartesian(polygon_xyz, point_xyz):
 
                 return weights, nodes
 
-        # If the point doesn't reside in the polygon, raise an error
-        raise ValueError("Point does not reside in polygon")
+        raise ValueError(
+            "Point does not reside in polygon, during "
+            "barycentric_coordinates_cartesian(polygon_xyz, point_xyz)"
+        )  # (can't do str(float) in numba --> can't include numbers here.)
 
 
 @njit(cache=True)