Improve docstrings

Author: Chahan Kropf

climada/engine/impact_calc.py

@@ -92,6 +92,8 @@ def impact(
             Default: True
         assign_centroids : bool, optional
             indicates whether centroids are assigned to the self.exposures object.
+            The default centroids assignement uses euclidean distance and a threshold equal to
+            twice the highest resolution of the centroids (assuming a regular grid).
             Recommendation: assign the centroids directly with control
             over the distance metric and the distance threshold using
             `exposure.assign_centroids(hazard)`. In this case, set assign_centroids to ``False``.

climada/entity/exposures/base.py

@@ -612,11 +612,11 @@ def assign_centroids(
             Possible values are "euclidean", "haversine" and "approx".
             Default: "euclidean"
         threshold : float
-            If the distance (in km) to the nearest neighbor exceeds `threshold`,
+            If the distance (in the exposure's crs) to the nearest neighbor exceeds `threshold`,
             the index `-1` is assigned.
             Set `threshold` to 0, to disable nearest neighbor matching and enforce
             exact matching.
-            Default: 100 (km)
+            Default: twice the highest resolution of the hazard centroids
         overwrite: bool
             If True, overwrite centroids already present. If False, do
             not assign new centroids. Default is True.
@@ -633,7 +633,7 @@ def assign_centroids(
         coordinates is needed, please use 'haversine' distance metric,
         which however is slower.
 
-        Caution: bearest neighbourg matching can introduce serious artefacts
+        Caution: nearest neighbourg matching can introduce serious artefacts
         such as:
             - exposure and hazard centroids with shifted grids can lead
             to systematically wrong assignements.

climada/util/coordinates.py

@@ -1190,6 +1190,8 @@ def match_coordinates(
     nearest neighbor. If the distance to the nearest neighbor exceeds `threshold`, the index `-1`
     is assigned.
 
+    Make sure that all coordinates are according to the same coordinate reference system (crs).
+
     You can disable nearest neighbor matching by setting `threshold` to 0, in which case
     only exactly matching coordinates are assigned to each other.
 
@@ -1205,9 +1207,9 @@ def match_coordinates(
     distance : str, optional
         Distance to use for non-exact matching. Possible values are "euclidean", "haversine" and
         "approx". Default: "euclidean"
-    unit : str, optional
-        Unit to use for non-exact matching. Possible values are "degree", "m", "km".
-        Default: "degree"
+    crs : str or pyproj crs, optinal
+        Coordinate reference system (crs) of the input coordinates.
+        Default: EPSG:4326
     threshold : float, optional
         If the distance to the nearest neighbor exceeds `threshold`, the index `-1` is assigned.
         Set `threshold` to 0 to disable nearest neighbor matching. Default: 100 (km or crs.unit)