fixing IndexError when opening nexrad Split Cut Mode file (#246)

* fixing IndexError when opening nexrad Split Cut Mode file
* fixing error with pytest
* running pre-commit
* running pre-commit
* Update xradar/io/backends/nexrad_level2.py
* adding split cut mode to comment in the global/root attributes
* attemp to fix lint and style checks errors
* documenting changes in history.md files

docs/history.md

@@ -6,6 +6,7 @@
 * FIX: Improving performance of `open_nexradlevel2_datatree` function and adding tests for `sweep` parameter. ({issue}`239`) ({pull}`240`) by [@aladinor](https://github.com/aladinor)
 * FIX: Keeping attributes at each variable when using `open_nexradlevel2_datatree`. ({issue}`241`) ({pull}`242`) by [@aladinor](https://github.com/aladinor)
 * FIX: Correctly read transition rays in RHI scans ({issue}`247`) ({pull}`250`) by [@rcjackson](https://github.com/rcjackson)
+* FIX: Correctly open NEXRAD files when split cut mode is enable ({issue} `245`) ({pull}`246`) by [@aladinor](https://github.com/aladinor)
 
 ## 0.8.0 (2024-11-04)
 

examples/notebooks/HaloPhotonics.ipynb

@@ -67,7 +67,7 @@
    "source": [
     "fig, ax = plt.subplots(3, 3, figsize=(12, 10))\n",
     "for sweep in range(9):\n",
-    "    sweep_ds = xd.georeference.get_x_y_z(ds[f\"sweep_{sweep:d}\"].ds)\n",
+    "    sweep_ds = xd.georeference.get_x_y_z(ds[f\"sweep_{sweep}\"].ds)\n",
     "    sweep_ds = sweep_ds.set_coords([\"x\", \"y\", \"z\", \"time\", \"range\"])\n",
     "    sweep_ds[\"mean_doppler_velocity\"].plot(\n",
     "        x=\"x\", y=\"y\", ax=ax[int(sweep / 3), sweep % 3]\n",
@@ -97,7 +97,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.4"
+   "version": "3.12.7"
   }
  },
  "nbformat": 4,

examples/notebooks/conftest.py

@@ -30,7 +30,7 @@ def collect(self):
             yield NotebookItem.from_parent(self, name=os.path.basename(f))
 
     def setup(self):
-        kernel = "python%d" % sys.version_info[0]  # noqa
+        kernel = f"python{sys.version_info[0]}"
         self.exproc = ExecutePreprocessor(kernel_name=kernel, timeout=600)
 
 

xradar/io/backends/common.py

@@ -126,6 +126,7 @@ def _assign_root(sweeps):
     attrs = {}
     attrs["Conventions"] = sweeps[0].attrs.get("Conventions", "None")
     attrs["instrument_name"] = sweeps[0].attrs.get("instrument_name", "None")
+    comment = sweeps[0].attrs.get("comment", None)
     attrs.update(
         {
             "version": "None",
@@ -137,6 +138,8 @@ def _assign_root(sweeps):
             "comment": "im/exported using xradar",
         }
     )
+    if comment is not None:
+        attrs["comment"] = attrs["comment"] + ",\n" + comment
     root = root.assign_attrs(attrs)
     # todo: pull in only CF attributes
     root = root.assign_attrs(sweeps[1].attrs)

xradar/io/backends/hpl.py

@@ -378,7 +378,7 @@ def __init__(self, filename, **kwargs):
                     sweep_dict[k] = data_unsorted[k][time_inds]
                 else:
                     sweep_dict[k] = data_unsorted[k]
-            self._data[f"sweep_{i:d}"] = sweep_dict
+            self._data[f"sweep_{i}"] = sweep_dict
         self._data["sweep_number"] = data_unsorted["sweep_number"]
         self._data["fixed_angle"] = data_unsorted["fixed_angle"]
 

xradar/io/backends/nexrad_level2.py

@@ -1591,7 +1591,7 @@ def open_nexradlevel2_datatree(
     """
     from xarray.core.treenode import NodePath
 
-    sweeps = []
+    comment = None
 
     if isinstance(sweep, str):
         sweep = NodePath(sweep).name
@@ -1610,6 +1610,12 @@ def open_nexradlevel2_datatree(
     else:
         with NEXRADLevel2File(filename_or_obj, loaddata=False) as nex:
             nsweeps = nex.msg_5["number_elevation_cuts"]
+            # Check if duplicated sweeps ("split cut mode")
+            n_sweeps = len(nex.msg_31_data_header)
+            if nsweeps > n_sweeps:
+                nsweeps = n_sweeps
+                comment = "Split Cut Mode scanning strategy"
+
         sweeps = [f"sweep_{i}" for i in range(nsweeps)]
 
     sweep_dict = open_sweeps_as_dict(
@@ -1631,6 +1637,8 @@ def open_nexradlevel2_datatree(
     )
     ls_ds: list[xr.Dataset] = [sweep_dict[sweep] for sweep in sweep_dict.keys()]
     ls_ds.insert(0, xr.Dataset())
+    if comment is not None:
+        ls_ds[0].attrs["comment"] = comment
     dtree: dict = {
         "/": _assign_root(ls_ds),
         "/radar_parameters": _get_subgroup(ls_ds, radar_parameters_subgroup),