Source code for trackintel.model.positionfixes

import geopandas as gpd
import pandas as pd

import trackintel as ti
from trackintel.model.util import (

_required_columns = ["user_id", "tracked_at"]

[docs] @_register_trackintel_accessor("as_positionfixes") class Positionfixes(TrackintelBase, TrackintelGeoDataFrame, gpd.GeoDataFrame): """Trackintel class to treat GeoDataFrames as collections of `Positionfixes`. Requires at least the following columns: ['user_id', 'tracked_at'] Requires valid point geometries; the 'index' of the GeoDataFrame will be treated as unique identifier of the `Positionfixes`. For several usecases, the following additional columns are required: ['elevation', 'accuracy' 'staypoint_id', 'tripleg_id'] Notes ----- In GPS based movement data analysis `Positionfixes` are the smallest unit of tracking and represent timestamped locations. 'tracked_at' is a timezone aware pandas datetime object. Examples -------- >>> positionfixes.generate_staypoints() """ def __init__(self, *args, validate=True, **kwargs): # could be moved to super class # validate kwarg is necessary as the object is not fully initialised if we call it from _constructor # (geometry-link is missing). thus we need a way to stop validating too early. super().__init__(*args, **kwargs) if validate: self.validate(self) # create circular reference directly -> avoid second call of init via accessor @property def as_positionfixes(self): return self @staticmethod def validate(obj): assert obj.shape[0] > 0, f"Geodataframe is empty with shape: {obj.shape}" # check columns if any([c not in obj.columns for c in _required_columns]): raise AttributeError( "To process a DataFrame as a collection of positionfixes, it must have the properties" f" {_required_columns}, but it has [{', '.join(obj.columns)}]." ) # check timestamp dtypes assert isinstance( obj["tracked_at"].dtype, pd.DatetimeTZDtype ), f"dtype of tracked_at is {obj['tracked_at'].dtype} but has to be datetime64 and timezone aware" # check geometry assert ( obj.geometry.is_valid.all() ), "Not all geometries are valid. Try x[~ x.geometry.is_valid] where x is you GeoDataFrame" if obj.geometry.iloc[0].geom_type != "Point": raise TypeError("The geometry must be a Point (only first checked).") @property def center(self): """Return the center coordinate of this collection of positionfixes.""" lat = self.geometry.y lon = self.geometry.x return (float(lon.mean()), float(lat.mean()))
[docs] def generate_staypoints( self, method="sliding", distance_metric="haversine", dist_threshold=100, time_threshold=5.0, gap_threshold=15.0, include_last=False, print_progress=False, exclude_duplicate_pfs=True, n_jobs=1, ): """ Generate staypoints based on positionfixes. See :func:`trackintel.preprocessing.generate_staypoints` for full documentation. """ return ti.preprocessing.generate_staypoints( self, method=method, distance_metric=distance_metric, dist_threshold=dist_threshold, time_threshold=time_threshold, gap_threshold=gap_threshold, include_last=include_last, print_progress=print_progress, exclude_duplicate_pfs=exclude_duplicate_pfs, n_jobs=n_jobs, )
[docs] def generate_triplegs( self, staypoints=None, method="between_staypoints", gap_threshold=15, ): """ Generate triplegs from positionfixes. See :func:`trackintel.preprocessing.generate_triplegs` for full documentation. """ return ti.preprocessing.generate_triplegs( self, staypoints=staypoints, method=method, gap_threshold=gap_threshold, )
[docs] def to_csv(self, filename, *args, **kwargs): """ Write positionfixes to csv file. See :func:`` for full documentation. """, filename, *args, **kwargs)
[docs] @doc(_shared_docs["write_postgis"], first_arg="", long="positionfixes", short="pfs") def to_postgis( self, name, con, schema=None, if_exists="fail", index=True, index_label=None, chunksize=None, dtype=None ):, name, con, schema, if_exists, index, index_label, chunksize, dtype)
[docs] def calculate_distance_matrix(self, Y=None, dist_metric="haversine", n_jobs=0, **kwds): """ Calculate a distance matrix based on a specific distance metric. See :func:`trackintel.geogr.calculate_distance_matrix` for full documentation. """ return ti.geogr.calculate_distance_matrix(self, Y=Y, dist_metric=dist_metric, n_jobs=n_jobs, **kwds)
[docs] def get_speed(self): """ Compute speed per positionfix (in m/s) See :func:`trackintel.geogr.get_speed_positionfixes` for full documentation. """ return ti.geogr.get_speed_positionfixes(self)