Add missing aliases to sphdistance

pygmt/src/sphdistance.py

@@ -16,8 +16,14 @@
 
 @fmt_docstring
 @use_alias(
+    C="single_form",
+    D="duplicate",
+    E="quantity",
     G="outgrid",
     I="spacing",
+    L="unit",
+    N="node_table",
+    Q="voronoi",
     R="region",
     V="verbose",
 )
@@ -50,7 +56,41 @@ def sphdistance(data=None, x=None, y=None, **kwargs):
     {I}
     {R}
     {V}
+    single_form : bool
+        For large data sets you can save some memory (at the expense of more
+        processing) by only storing one form of location coordinates
+        (geographic or Cartesian 3-D vectors) at any given time, translating
+        from one form to the other when necessary [Default keeps both arrays
+        in memory]. Not applicable with ``voronoi``.
+    duplicate : bool
+        Used to skip duplicate points since the algorithm cannot handle them.
+        [Default assumes there are no duplicates].
+    quantity : str
+        **d**\|\ **n**\|\ **z**\ [*dist*]
+        Specify the quantity that should be assigned to the grid nodes [Default
+        is **d**]:
 
+        - **d** - compute distances to the nearest data point
+        - **n** - assign the ID numbers of the Voronoi polygons that each
+          grid node is inside
+        - **z** - assign all nodes inside the polygon the z-value of the center
+          node fot a natural nearest-neighbor grid.
+
+        Optionally, append the resampling interval along Voronoi arcs in
+        spherical degrees.
+    unit : str
+        Specify the unit used for distance calculations. Choose among **d**
+        (spherical degree), **e** (m), **f** (feet), **k** (km), **M**
+        (mile), **n** (nautical mile) or **u** survey foot.
+    node_table : str
+        Read the information pertaining to each Voronoi
+        polygon (the unique node lon, lat and polygon area) from a separate
+        file [Default acquires this information from the ASCII segment
+        headers of the output file]. Required if binary input via `voronoi`
+        is used.
+    voronoi : str
+        Append the name of a file with pre-calculated Voronoi polygons
+        [Default performs the Voronoi construction on input data].
     Returns
     -------
     ret: xarray.DataArray or None