Integration with lonboard

src/traffic/core/flight.py

@@ -57,6 +57,7 @@
 if TYPE_CHECKING:
     import altair as alt
     import plotly.graph_objects as go
+    import pyarrow as pa
     from cartopy import crs
     from cartopy.mpl.geoaxes import GeoAxes
     from ipyleaflet import Map as LeafletMap
@@ -679,13 +680,13 @@ def label(
 
             .. code:: python
 
-                flight.label(holding_pattern, holding=True)
+                flight.label('holding_pattern', holding=True)
 
         - Add a column `index` to enumerate holding patterns:
 
             .. code:: python
 
-                flight.label(holding_pattern, index="{i}")
+                flight.label('holding_pattern', index="{i}")
 
         - More complicated enriching:
 
@@ -1903,6 +1904,69 @@ def forward(
             ).ffill()
         )
 
+    def pyarrow_table(
+        self,
+        columns: None | list[str] = None,
+        geo: None | Literal["line2d", "line3d", "point2d", "point3d"] = None,
+    ) -> "pa.Table":
+        import pyarrow as pa
+
+        len_ = len(self)
+
+        default_columns = ["track", "groundspeed", "altitude", "vertical_rate"]
+        if columns is None:
+            columns = default_columns
+        else:
+            columns += default_columns
+
+        entry = dict(
+            icao24=pa.array([self.icao24]),
+            timestamp=pa.ListArray.from_arrays([0, len_], self.data.timestamp),
+        )
+
+        if (callsign := self.callsign) is not None:
+            entry["callsign"] = pa.array([callsign])
+
+        if (flight_id := self.flight_id) is not None:
+            entry["flight_id"] = pa.array([flight_id])
+
+        # The usual features
+        for col in columns:
+            if col in self.data.columns:
+                entry[col] = pa.ListArray.from_arrays([0, len_], self.data[col])
+
+        pa_table = pa.table(entry)
+
+        # The geometric feature
+        if geo is not None:
+            coords = [
+                self.data.longitude,
+                self.data.latitude,
+            ]
+            if geo in ["line3d", "point3d"]:
+                coords.append(self.data.altitude)
+
+            extension_name = dict(
+                line2d="geoarrow.linestring",
+                line3d="geoarrow.linestring",
+                point2d="geoarrow.multipoint",
+                point3d="geoarrow.multipoint",
+            )
+
+            np_coords = np.column_stack(coords).ravel("C")
+            pa_coords = pa.FixedSizeListArray.from_arrays(
+                np_coords, list_size=len(coords)
+            )
+            pa_linestrings = pa.ListArray.from_arrays([0, len_], pa_coords)
+            pa_field = pa.field(
+                "geometry",
+                pa_linestrings.type,
+                metadata={"ARROW:extension:name": extension_name[geo]},
+            )
+            pa_table = pa_table.append_column(pa_field, pa_linestrings)
+
+        return pa_table
+
     # -- Air traffic management --
 
     def assign_id(

src/traffic/core/traffic.py

@@ -3,6 +3,7 @@
 import logging
 import warnings
 from datetime import timedelta
+from itertools import accumulate
 from pathlib import Path
 from typing import (
     TYPE_CHECKING,
@@ -45,6 +46,7 @@
 
 if TYPE_CHECKING:
     import plotly.graph_objects as go
+    import pyarrow as pa
     from cartopy import crs
     from cartopy.mpl.geoaxes import GeoAxesSubplot
     from ipyleaflet import Map as LeafletMap
@@ -753,6 +755,10 @@ def all(self, *args, **kwargs):  # type: ignore
     def next(self, *args, **kwargs):  # type: ignore
         ...
 
+    @lazy_evaluation()
+    def label(self, *args, **kwargs):  # type: ignore
+        ...
+
     @lazy_evaluation()
     def final(self, *args, **kwargs):  # type: ignore
         ...
@@ -1047,6 +1053,69 @@ def basic_stats(self) -> pd.DataFrame:
     @lazy_evaluation()
     def summary(self, attributes: list[str]) -> pd.DataFrame: ...
 
+    def pyarrow_table(
+        self,
+        columns: None | list[str] = None,
+        geo: None | Literal["line2d", "line3d", "point2d", "point3d"] = None,
+    ) -> "pa.Table":
+        import pyarrow as pa
+
+        summary = cast(
+            pd.DataFrame,
+            self.summary(["icao24", "callsign", "flight_id", "count"]).eval(),
+        )
+        offsets = [0, *accumulate(summary["count"])]
+
+        default_columns = ["track", "groundspeed", "altitude", "vertical_rate"]
+        if columns is None:
+            columns = default_columns
+        else:
+            columns += default_columns
+
+        entry = dict(
+            icao24=pa.array(list(summary["icao24"])),
+            callsign=pa.array(list(summary["callsign"])),
+            flight_id=pa.array(list(summary["flight_id"])),
+            timestamp=pa.ListArray.from_arrays(offsets, self.data.timestamp),
+        )
+
+        # The usual features
+        for col in columns:
+            if col in self.data.columns:
+                entry[col] = pa.ListArray.from_arrays(offsets, self.data[col])
+
+        pa_table = pa.table(entry)
+
+        # The geometric feature
+        if geo is not None:
+            coords = [
+                self.data.longitude,
+                self.data.latitude,
+            ]
+            if geo in ["line3d", "point3d"]:
+                coords.append(self.data.altitude)
+
+            extension_name = dict(
+                line2d="geoarrow.linestring",
+                line3d="geoarrow.linestring",
+                point2d="geoarrow.multipoint",
+                point3d="geoarrow.multipoint",
+            )
+
+            np_coords = np.column_stack(coords).ravel("C")
+            pa_coords = pa.FixedSizeListArray.from_arrays(
+                np_coords, list_size=len(coords)
+            )
+            pa_linestrings = pa.ListArray.from_arrays(offsets, pa_coords)
+            pa_field = pa.field(
+                "geometry",
+                pa_linestrings.type,
+                metadata={"ARROW:extension:name": extension_name[geo]},
+            )
+            pa_table = pa_table.append_column(pa_field, pa_linestrings)
+
+        return pa_table
+
     def geoencode(self, *args: Any, **kwargs: Any) -> NoReturn:
         """
         .. danger::