BugFix: Added check for empty points in DBSCAN clustering function.

Author: helvecioneto

examples/02_Track-Radar-Data/02_Track-Radar-Dataset.ipynb

@@ -70,6 +70,17 @@
     "!python -m pip install -q -U pyfortracc"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Import libraries and check pyfortracc version\n",
+    "import pyfortracc\n",
+    "print(f'pyfortracc version: {pyfortracc.__version__}')"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -194,8 +205,8 @@
     "name_list['input_path'] = 'input/' # path to the input data\n",
     "name_list['output_path'] = 'output/' # path to the output data\n",
     "name_list['timestamp_pattern'] = 'sbmn_cappi_%Y%m%d_%H%M.nc.gz' # timestamp file pattern\n",
-    "name_list['thresholds'] = [20,30,35] # in dbz\n",
-    "name_list['min_cluster_size'] = [3,3,3] # in number of points per cluster\n",
+    "name_list['thresholds'] = [20, 30, 35] # in dbz\n",
+    "name_list['min_cluster_size'] = [5,4,3] # in number of points per cluster\n",
     "name_list['operator'] = '>=' # '>= *   **<=' or '=='\n",
     "name_list['delta_time'] = 12 # in minutes\n",
     "name_list['min_overlap'] = 20 # Minimum overlap between clusters in percentage\n",
@@ -229,7 +240,7 @@
     "import pyfortracc as pf\n",
     "\n",
     "# Track the clusters\n",
-    "pf.track(name_list, read_function)"
+    "pf.track(name_list, read_function, parallel=False)"
    ]
   },
   {

examples/WORCAP-Minicourse/4_Sunspots_Tracking/4_Sunspots_Tracking.ipynb

@@ -59,6 +59,12 @@ def dbscan_clustering(data, operator, threshold, min_size, eps=1):
     """
     # Segment the data based on the threshold
     points = np.argwhere(operator(data, threshold))
+    # Check if have points after filtering based on operator
+    if points.size == 0:
+        # Return empty clusters and labels
+        clusters = np.zeros(data.shape, dtype=np.int32)
+        labels = np.empty((0, 3), dtype=np.int32)
+        return clusters, labels
     # Set the dbscan object
     dbscan = DBSCAN(algorithm='kd_tree', metric='chebyshev',
                     eps=eps, min_samples=3)