cvts package¶

Subpackages¶

cvts.tasks package
- Module contents

Submodules¶

cvts.models module¶

Module providing an ORM for objects of interest.

class cvts.models.Base(**kwargs)¶

Bases: sqlalchemy.orm.decl_api.Base

The location a vehicle is garraged.

id¶

lat¶

lon¶

vehicle¶

vehicle_id¶

class cvts.models.Stop(**kwargs)¶

Bases: sqlalchemy.orm.decl_api.Base

The location a vehicle is garraged.

end_lat¶

end_lon¶

end_time¶

id¶

n_stationary¶

start_end_dist¶

start_lat¶

start_lon¶

start_time¶

vehicle¶

vehicle_id¶

class cvts.models.Traversal(**kwargs)¶

Bases: sqlalchemy.orm.decl_api.Base

A traversal of a Segment.

count¶

dow¶

doy¶

edge¶

hour¶

id¶

speed¶

timestamp¶

trip¶

trip_id¶

vehicle¶

vehicle_id¶

woy¶

class cvts.models.Trip(**kwargs)¶

Bases: sqlalchemy.orm.decl_api.Base

The location a vehicle is garraged.

end¶

end_id¶

id¶

start¶

start_id¶

vehicle¶

vehicle_id¶

class cvts.models.Vehicle(**kwargs)¶

Bases: sqlalchemy.orm.decl_api.Base

Data on a vehicle.

etl_id¶

id¶

rego¶

vehicle_type¶

vehicle_type_id¶

class cvts.models.VehicleType(**kwargs)¶

Bases: sqlalchemy.orm.decl_api.Base

A list of vehicle types.

code¶

group¶

id¶

type_en¶

type_vn¶

cvts.settings module¶

cvts.settings.BOUNDARIES_PATH = '/home/kna012/.cvts/boundaries'¶: Directory for shape files for geographies.

cvts.settings.CONFIG_PATH = '/home/kna012/.cvts/config'¶: Directory containing VALHALLA_CONFIG_FILE

cvts.settings.DEBUG = False¶: Are we debugging. Can be set via the environment variable CVTS_DEBUG.

cvts.settings.EARTH_RADIUS = 6371000¶: Radius of the Earth in meters.

cvts.settings.LAKE_FLAG = 'lake'¶: String used to denote stuff from the lake

cvts.settings.MIN_DISTANCE_BETWEEN_STOPS = 50¶: The distance between two stops below which they are considered to be the same location.

cvts.settings.MIN_MOVE_DISTANCE = 50¶: The minimum distance a vehicle can move between two (potentially non-adjacent) GPS points to not be considered ‘moving’ in meters.

cvts.settings.MIN_MOVING_SPEED = 4¶: The minimum speed a vehicle can be moving to be considered ‘moving’ in kilometers per hour.

cvts.settings.MIN_STOP_TIME = 480¶: The minimum time a vehicle must not move for to be considered ‘stopped’ in seconds.

cvts.settings.OUT_PATH = '~/.cvts/output'¶: Root directory for outputs.

cvts.settings.POSTGRES_CONNECTION_STRING = None¶: The connection string for PostGRE. Read from the environment variable CVTS_POSTGRES_CONNECTION_STRING.

cvts.settings.RAW_DATA_FILE_EXTENSIONS = ['.csv']¶: Extensions for the input files to keep. Only used if RAW_DATA_FORMAT is RawDataFormat.CSV or RawDataFormat.GZIP.

cvts.settings.RAW_DATA_FORMAT = RawDataFormat.CSV¶: The format the raw data is stored in.

cvts.settings.RAW_PATH = '/home/kna012/.cvts/raw'¶: Root directory for input files.

class cvts.settings.RawDataFormat(value)¶

Bases: enum.Enum

An enumeration.

CSV = 1¶

GZIP = 3¶

cvts.settings.SEQ_PATH = '~/.cvts/output/seq'¶: Output directory for trip outputs.

cvts.settings.SPEED_PATH = '~/.cvts/output/speed'¶: Output directory for speed outputs.

cvts.settings.SRC_DEST_PATH = '~/.cvts/output/src_dest'¶: Output directory for source/destination outputs.

cvts.settings.STOP_PATH = '~/.cvts/output/stop'¶: Output directory for stop points.

cvts.settings.VALHALLA_CONFIG_FILE = '/home/kna012/.cvts/config/valhalla.json'¶: Path to Valhalla configuration file.

cvts.settings.WORK_PATH = '~/.cvts'¶: Default root directory

cvts.settings.setup_logging(level=20)¶

Module contents¶

exception cvts.DataLakeError¶: Bases: Exception

exception cvts.NoRawDataException¶: Bases: Exception

class cvts.RawDataFormat(value)¶

Bases: enum.Enum

An enumeration.

CSV = 1¶

GZIP = 3¶

cvts.distance(x0, y0, x1, y1)¶

Quick and adequate distance calculation for for small distances in meters between two lon/lats.

This should be adequate for the purpose of measuring points between points in the kinds of GPS traces we are working with, where the typical sampling interval is around 15 seconds (i.e., differences in latitude between y0 and y1 are (very) small).

Parameters

x0 (float) – First longitude.
y0 (float) – First latitude.
x1 (float) – Second longitude.
y1 (float) – Second latitude.

Returns

Approximate distance between the two points in meters.

cvts.json2geojson(data, shape_only)¶

Convert the output from Valhalla to a GeoJSON object.

On the command line, the call would look like:

valhalla_service <config-file> trace_attributes <input-file>

Parameters

data (Dict[str, Any]) – Output of a call to Valhalla (as described above).
shape_only (bool) – Should the returned GeoJSON only include the shape element from data?

Return type

Dict[str, Any]

Returns

TODO

cvts.jsonfile2geojsonfile(infile, outfile)¶

cvts.points_to_polys(points, shapedata)¶

Calculate which geometry each point in points lie within.

Parameters

points (NDArray) – Two column numpy array containing the longitudes and latitudes of the address points.
shapedata (str) – tuple containing geometry IDs, polygions and bounding boxes for a geography.

Return type

NDArray

Returns

The geometry ID for each point.

cvts.rawfiles2jsonchunks(input_descriptor, split_trips, dates)¶

Create a generator over all the data for a single vehicle from data in a csv or iterable of csvs.

Parameters

input_descriptor (Union[str, Iterable[str]]) – Either the name of a GPS data file or an iterable of names of such files.
split_trips (bool) – if True, then split into trips, otherwise return all points as a single ‘trip’.
dates (Iterable[datetime.date]) –

Return type

Generator[Dict[str, Any], None, None]

Returns

A geenerator over a dicts that contain information about each GPS point. Each dict looks like:

{
    'lat':     float(row['Longitude']),
    'lon':     float(row['Latitude']),
    'time':    float(row['Time']),
    'heading': float(row['Orientation']),
    'speed':   float(row['speed']),
    'heading_tolerance': 45,
    'type':    'via'
}

cvts.rawfiles2jsonfile(csv_file, out_file)¶

Call rawfiles2jsonchunks(), passing csv_files and False, and write the result to out_file.

Parameters

csv_file (Union[str, Iterable[str]]) – Either the name of a GPS data file or an iterable of names of such files.
out_file (str) – The path of the file to write the trip to.

cvts.read_shapefile(filename, geometry_id_field)¶

Load the data from a shapefile.

Parameters

filename (str) – The name of the shapefile.
geometry_id_field (str) – The field to extract from the shapefile. This should contain the identifier for the geometries.

Return type

str

Returns

The name of the file the data in the shapefile was saved to.

cvts.vehicle_ids()¶