Add doc

Author: HCookie

docs/inference/configs/inputs.rst

@@ -51,6 +51,39 @@ You can specify the input as ``grib`` to read the data from a GRIB file.
 
 For more options, see :ref:`grib-input`.
 
+********
+ netcdf
+********
+
+You can specify the input as ``netcdf`` to read the data from a NetCDF
+file.
+
+.. literalinclude:: yaml/inputs_5.yaml
+   :language: yaml
+
+.. note::
+
+   The netcdf input expects the data to be stored identically to the
+   GRIB input, i.e. with a values coordinate, and variable names that
+   match what the checkpoint was trained on.
+
+   For context, using ``earthkit-data`` a grib file can be exported as
+   netcdf with the following and then read back in using the netcdf
+   input, note how the names are created:
+
+   .. code:: python
+
+      import earthkit.data as ekd
+
+      ds = ekd.from_source("file", "input.grib")
+
+      ds_xr = ds.to_xarray(
+          variable_key="p_l",
+          remapping={"p_l": "{param}_{levelist}"},
+          add_earthkit_attrs=False,
+      )
+      ds_xr.to_netcdf("input.nc")
+
 ******
  mars
 ******

docs/inference/configs/yaml/inputs_5.yaml

@@ -0,0 +1,2 @@
+input:
+  netcdf: /path/to/netcdf/file.nc