Added Typing

.prettierrc.toml

@@ -1,3 +1,3 @@
-tabWidth = 2
+tabWidth = 4
 semi = false
 singleQuote = true

xesmf/backend.py

@@ -26,7 +26,7 @@
 import numpy.lib.recfunctions as nprec
 
 
-def warn_f_contiguous(a):
+def warn_f_contiguous(a: np.ndarray) -> None:
     """
     Give a warning if input array if not Fortran-ordered.
 
@@ -41,7 +41,7 @@ def warn_f_contiguous(a):
         warnings.warn('Input array is not F_CONTIGUOUS. ' 'Will affect performance.')
 
 
-def warn_lat_range(lat):
+def warn_lat_range(lat: np.ndarray) -> None:
     """
     Give a warning if latitude is outside of [-90, 90]
 
@@ -58,7 +58,13 @@ def warn_lat_range(lat):
 
 class Grid(ESMF.Grid):
     @classmethod
-    def from_xarray(cls, lon, lat, periodic=False, mask=None):
+    def from_xarray(
+        cls,
+        lon: np.ndarray[float, int],
+        lat: np.ndarray[float, int],
+        periodic: bool = False,
+        mask=None,
+    ):
         """
         Create an ESMF.Grid object, for constructing ESMF.Field and ESMF.Regrid.
 
@@ -158,7 +164,7 @@ def from_xarray(cls, lon, lat):
         Parameters
         ----------
         lon, lat : 1D numpy array
-             Longitute/Latitude of cell centers.
+            Longitute/Latitude of cell centers.
 
         Returns
         -------

xesmf/data.py

@@ -3,42 +3,45 @@
 """
 
 import numpy as np
+import xarray
 
 
-def wave_smooth(lon, lat):
-    r"""
+def wave_smooth(  # type: ignore
+    lon: np.ndarray[float] | xarray.DataArray,  # type: ignore
+    lat: np.ndarray[float] | xarray.DataArray,  # type: ignore
+) -> np.ndarray[float] | xarray.DataArray:  # type: ignore
+    """
     Spherical harmonic with low frequency.
 
     Parameters
     ----------
     lon, lat : 2D numpy array or xarray DataArray
-         Longitute/Latitude of cell centers
+            Longitute/Latitude of cell centers
 
     Returns
     -------
-    f : 2D numpy array or xarray DataArray depending on input
-        2D wave field
+    f : 2D numpy array or xarray DataArray depending on input2D wave field
 
     Notes
     -------
     Equation from [1]_ [2]_:
 
-    .. math:: Y_2^2 = 2 + \cos^2(\\theta) \cos(2 \phi)
+    .. math:: Y_2^2 = 2 + cos^2(lat) * cos(2 * lon)
 
     References
     ----------
     .. [1] Jones, P. W. (1999). First-and second-order conservative remapping
-       schemes for grids in spherical coordinates. Monthly Weather Review,
-       127(9), 2204-2210.
+        schemes for grids in spherical coordinates. Monthly Weather Review,
+        127(9), 2204-2210.
 
     .. [2] Ullrich, P. A., Lauritzen, P. H., & Jablonowski, C. (2009).
-       Geometrically exact conservative remapping (GECoRe): regular
-       latitude–longitude and cubed-sphere grids. Monthly Weather Review,
-       137(6), 1721-1741.
+        Geometrically exact conservative remapping (GECoRe): regular
+        latitude-longitude and cubed-sphere grids. Monthly Weather Review,
+        137(6), 1721-1741.
     """
     # degree to radius, make a copy
-    lat = lat / 180.0 * np.pi
-    lon = lon / 180.0 * np.pi
+    lat *= np.pi / 180.0  # type: ignore
+    lon *= np.pi / 180.0  # type: ignore
 
-    f = 2 + np.cos(lat) ** 2 * np.cos(2 * lon)
+    f = 2 + pow(np.cos(lat), 2) * np.cos(2 * lon)  # type: ignore
     return f