obspy.clients.fdsn.mass_downloader.domain.Domain

class Domain

Bases: object

Abstract base class defining a domain - subclass it to define a new domain.

Each subclass must implement the get_query_parameters() method and optionally the is_in_domain() method which enables the construction of arbitrarily complex domains. The get_query_parameters() method must return the query parameters to download as much data as required. The is_in_domain() can later be used to refine the domain after the data has been downloaded.

It can be thought of as a boolean operation - first the rough domain is specified including all the possible points, then some points are removed again. This is illustrated with an example domain representing Germany utilizing the external packages shapely and fiona. Shapefiles can be found online on many websites, for example on http://www.gadm.org/. The example works by first extracting the bounds of the country to formulate the FDSN query and then removing points outside of the exact shape.

import fiona
import shapely.geometry

from obspy.clients.fdsn.mass_downloader import Domain


class Germany(Domain):
    def __init__(self):
        Domain.__init__(self)

        fiona_collection = fiona.open("./DEU_adm/DEU_adm0.shp")
        geometry = fiona_collection.next()["geometry"]

        self.shape = shapely.geometry.asShape(geometry)
        self.b = fiona_collection.bounds

    def get_query_parameters(self):
        return {"minlatitude": self.b[1],
                "minlongitude": self.b[0],
                "maxlatitude": self.b[3],
                "maxlongitude": self.b[2]}

    def is_in_domain(self, latitude, longitude):
        if self.shape.contains(shapely.geometry.Point(longitude,
                                                      latitude)):
            return True
        return False

This is further illustrated by the following image. The green rectangle denotes the original FDSN query which returns the blue points. In the second step the red points are discarded leaving only points (stations) within Germany.

Public Methods

get_query_parameters	Return the domain specific query parameters for the get_stations() method as a dictionary.
is_in_domain	Returns True/False depending on the point being in the domain.

Special Methods

Domain.__delattr__(name, /)

Implement delattr(self, name).

Domain.__dir__()

Default dir() implementation.

Domain.__eq__(value, /)

Return self==value.

Domain.__format__(format_spec, /)

Default object formatter.

Domain.__ge__(value, /)

Return self>=value.

Domain.__getattribute__(name, /)

Return getattr(self, name).

Domain.__gt__(value, /)

Return self>value.

Domain.__hash__()

Return hash(self).

Domain.__init__()

Domain.__init_subclass__()

This method is called when a class is subclassed.

The default implementation does nothing. It may be overridden to extend subclasses.

Domain.__le__(value, /)

Return self<=value.

Domain.__lt__(value, /)

Return self<value.

Domain.__ne__(value, /)

Return self!=value.

Domain.__new__(**kwargs)

Domain.__reduce__()

Helper for pickle.

Domain.__reduce_ex__(protocol, /)

Helper for pickle.

Domain.__repr__()

Return repr(self).

Domain.__setattr__(name, value, /)

Implement setattr(self, name, value).

Domain.__sizeof__()

Size of object in memory, in bytes.

Domain.__str__()

Return str(self).

Domain.__subclasshook__()

Abstract classes can override this to customize issubclass().

This is invoked early on by abc.ABCMeta.__subclasscheck__(). It should return True, False or NotImplemented. If it returns NotImplemented, the normal algorithm is used. Otherwise, it overrides the normal algorithm (and the outcome is cached).