Add ExtractStopsAlgorithm

Author: anitagraser

qgis_processing/extractPtsAlgorithm.py

@@ -7,14 +7,20 @@
 from qgis.core import (
     QgsProcessingParameterExtent,
     QgsProcessingParameterVectorLayer,
+    QgsProcessingParameterNumber,
+    QgsProcessingParameterString,
     QgsProcessingParameterFeatureSink,
     QgsProcessing,
     QgsWkbTypes,
     QgsField,
     QgsFeatureSink,
+    QgsFields,
 )
 from qgis.core import QgsMessageLog, Qgis
 
+import pandas as pd
+from movingpandas import TrajectoryStopDetector
+
 sys.path.append("..")
 
 from .trajectoriesAlgorithm import TrajectoriesAlgorithm
@@ -114,3 +120,99 @@ def processTc(self, tc, parameters, context):
         for _, row in gdf.iterrows():
             f = feature_from_gdf_row(row)
             self.sink_dest.addFeature(f, QgsFeatureSink.FastInsert)
+
+
+class ExtractStopsAlgorithm(TrajectoriesAlgorithm):
+    MAX_DIAMETER = "MAX_DIAMETER"
+    MIN_DURATION = "MIN_DURATION"
+    STOP_PTS = "STOP_PTS"
+
+    def __init__(self):
+        super().__init__()
+
+    def initAlgorithm(self, config=None):
+        super().initAlgorithm(config)
+        self.addParameter(
+            QgsProcessingParameterNumber(
+                name=self.MAX_DIAMETER,
+                description=self.tr("Max stop diameter (meters)"),
+                defaultValue=30,
+                optional=False,
+            )
+        )
+        self.addParameter(
+            QgsProcessingParameterString(
+                name=self.MIN_DURATION,
+                description=self.tr(
+                    "Min stop duration (timedelta, e.g. 1 hours, 15 minutes)"
+                ),
+                defaultValue="2 minutes",
+                optional=False,
+            )
+        )
+        self.addParameter(
+            QgsProcessingParameterFeatureSink(
+                name=self.STOP_PTS,
+                description=self.tr("Stop points"),
+                type=QgsProcessing.TypeVectorPoint,
+            )
+        )
+
+    def group(self):
+        return self.tr("Basic")
+
+    def groupId(self):
+        return "TrajectoryBasic"
+
+    def name(self):
+        return "extract_stop_pts"
+
+    def displayName(self):
+        return self.tr("Extract stop points")
+
+    def shortHelpString(self):
+        return self.tr("<p>Extracts stop points from trajectories.</p>")
+
+    def processAlgorithm(self, parameters, context, feedback):
+        tc, crs = self.create_tc(parameters, context)
+
+        self.fields_pts = QgsFields()
+        self.fields_pts.append(QgsField("stop_id", QVariant.String))
+        self.fields_pts.append(QgsField("start_time", QVariant.String))  # .DateTime))
+        self.fields_pts.append(QgsField("end_time", QVariant.String))  # .DateTime))
+        self.fields_pts.append(QgsField("traj_id", QVariant.String))
+        self.fields_pts.append(QgsField("duration_s", QVariant.Double))
+
+        (self.sink, self.stop_pts) = self.parameterAsSink(
+            parameters,
+            self.STOP_PTS,
+            context,
+            self.fields_pts,
+            QgsWkbTypes.Point,
+            crs,
+        )
+
+        self.processTc(tc, parameters, context)
+
+        return {self.STOP_PTS: self.stop_pts}
+
+    def processTc(self, tc, parameters, context):
+        max_diameter = self.parameterAsDouble(parameters, self.MAX_DIAMETER, context)
+        min_duration = self.parameterAsString(parameters, self.MIN_DURATION, context)
+        min_duration = pd.Timedelta(min_duration).to_pytimedelta()
+
+        gdf = TrajectoryStopDetector(tc).get_stop_points(
+            max_diameter=max_diameter, min_duration=min_duration
+        )
+        gdf = gdf.convert_dtypes()
+        gdf["stop_id"] = gdf.index.astype(str)
+        gdf["start_time"] = gdf["start_time"].astype(str)
+        gdf["end_time"] = gdf["end_time"].astype(str)
+
+        names = [field.name() for field in self.fields_pts]
+        names.append("geometry")
+        gdf = gdf[names]
+
+        for _, row in gdf.iterrows():
+            f = feature_from_gdf_row(row)
+            self.sink.addFeature(f, QgsFeatureSink.FastInsert)

qgis_processing/splitTrajectoriesAlgorithm.py

@@ -139,7 +139,7 @@ def initAlgorithm(self, config=None):
             QgsProcessingParameterNumber(
                 name=self.MAX_DIAMETER,
                 description=self.tr("Max stop diameter (meters)"),
-                defaultValue=15,
+                defaultValue=30,
                 optional=False,
             )
         )
@@ -149,7 +149,7 @@ def initAlgorithm(self, config=None):
                 description=self.tr(
                     "Min stop duration (timedelta, e.g. 1 hours, 15 minutes)"
                 ),
-                defaultValue="15 minutes",
+                defaultValue="2 minutes",
                 optional=False,
             )
         )

qgis_processing/trajectoolsProvider.py

@@ -18,7 +18,7 @@
     ClipTrajectoriesByExtentAlgorithm,
     ClipTrajectoriesByPolygonLayer,
 )
-from .extractPtsAlgorithm import ExtractODPtsAlgorithm
+from .extractPtsAlgorithm import ExtractODPtsAlgorithm, ExtractStopsAlgorithm
 
 pluginPath = os.path.dirname(__file__)
 
@@ -59,6 +59,7 @@ def getAlgs(self):
             ClipTrajectoriesByExtentAlgorithm(),
             ClipTrajectoriesByPolygonLayer(),
             ExtractODPtsAlgorithm(),
+            ExtractStopsAlgorithm(),
         ]
         return algs