.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "tutorials/catalog_filtering.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_tutorials_catalog_filtering.py: .. tutorial-catalog-filtering Catalogs operations =================== This example demonstrates how to perform standard operations on a catalog. This example requires an internet connection to access ComCat. Overview: 1. Load catalog from ComCat 2. Create filtering parameters in space, magnitude, and time 3. Filter catalog using desired filters 4. Write catalog to standard CSEP format .. GENERATED FROM PYTHON SOURCE LINES 18-23 Load required libraries ----------------------- Most of the core functionality can be imported from the top-level :mod:`csep` package. Utilities are available from the :mod:`csep.utils` subpackage. .. GENERATED FROM PYTHON SOURCE LINES 23-29 .. code-block:: Python import csep from csep.core import regions from csep.utils import time_utils, comcat # sphinx_gallery_thumbnail_path = '_static/CSEP2_Logo_CMYK.png' .. GENERATED FROM PYTHON SOURCE LINES 30-36 Load catalog ------------ PyCSEP provides access to the ComCat web API using :func:`csep.query_comcat` and to the Bollettino Sismico Italiano API using :func:`csep.query_bsi`. These functions require a :class:`datetime.datetime` to specify the start and end dates. .. GENERATED FROM PYTHON SOURCE LINES 36-42 .. code-block:: Python start_time = csep.utils.time_utils.strptime_to_utc_datetime('2019-01-01 00:00:00.0') end_time = csep.utils.time_utils.utc_now_datetime() catalog = csep.query_comcat(start_time, end_time) print(catalog) .. rst-class:: sphx-glr-script-out .. code-block:: none Fetched ComCat catalog in 21.963388919830322 seconds. Downloaded catalog from ComCat with following parameters Start Date: 2019-01-01 12:01:46.950000+00:00 End Date: 2024-03-11 23:07:48.760000+00:00 Min Latitude: 31.5025 and Max Latitude: 42.8543333333333 Min Longitude: -125.3975 and Max Longitude: -113.1001667 Min Magnitude: 2.5 Found 10617 events in the ComCat catalog. Name: None Start Date: 2019-01-01 12:01:46.950000+00:00 End Date: 2024-03-11 23:07:48.760000+00:00 Latitude: (31.5025, 42.8543333333333) Longitude: (-125.3975, -113.1001667) Min Mw: 2.5 Max Mw: 7.1 Event Count: 10617 .. GENERATED FROM PYTHON SOURCE LINES 43-49 Filter to magnitude range ------------------------- Use the :meth:`csep.core.catalogs.AbstractBaseCatalog.filter` to filter the catalog. The filter function uses the field names stored in the numpy structured array. Standard fieldnames include 'magnitude', 'origin_time', 'latitude', 'longitude', and 'depth'. .. GENERATED FROM PYTHON SOURCE LINES 49-53 .. code-block:: Python catalog = catalog.filter('magnitude >= 3.5') print(catalog) .. rst-class:: sphx-glr-script-out .. code-block:: none Name: None Start Date: 2019-01-13 09:35:49.870000+00:00 End Date: 2024-03-10 11:23:37.644000+00:00 Latitude: (31.5071, 42.7775) Longitude: (-125.3868333, -113.1191667) Min Mw: 3.5 Max Mw: 7.1 Event Count: 1294 .. GENERATED FROM PYTHON SOURCE LINES 54-62 Filter to desired time interval ------------------------------- We need to define desired start and end times for the catalog using a time-string format. PyCSEP uses integer times for doing time manipulations. Time strings can be converted into integer times using :func:`csep.utils.time_utils.strptime_to_utc_epoch`. The :meth:`csep.core.catalog.AbstractBaseCatalog.filter` also accepts a list of strings to apply multiple filters. Note: The number of events may differ if this script is ran at a later date than shown in this example. .. GENERATED FROM PYTHON SOURCE LINES 62-72 .. code-block:: Python # create epoch times from time-string formats start_epoch = csep.utils.time_utils.strptime_to_utc_epoch('2019-07-06 03:19:54.040000') end_epoch = csep.utils.time_utils.strptime_to_utc_epoch('2019-09-21 03:19:54.040000') # filter catalog to magnitude ranges and times filters = [f'origin_time >= {start_epoch}', f'origin_time < {end_epoch}'] catalog = catalog.filter(filters) print(catalog) .. rst-class:: sphx-glr-script-out .. code-block:: none Name: None Start Date: 2019-07-06 03:20:36.080000+00:00 End Date: 2019-09-19 09:59:46.580000+00:00 Latitude: (32.2998352, 41.1244) Longitude: (-125.0241667, -115.3243332) Min Mw: 3.5 Max Mw: 5.5 Event Count: 356 .. GENERATED FROM PYTHON SOURCE LINES 73-82 Filter to desired spatial region -------------------------------- We use a circular spatial region with a radius of 3 average fault lengths as defined by the Wells and Coppersmith scaling relationship. PyCSEP provides :func:`csep.utils.spatial.generate_aftershock_region` to create an aftershock region based on the magnitude and epicenter of an event. We use :func:`csep.utils.comcat.get_event_by_id` the ComCat API provided by the USGS to obtain the event information from the M7.1 Ridgecrest mainshock. .. GENERATED FROM PYTHON SOURCE LINES 82-95 .. code-block:: Python m71_event_id = 'ci38457511' event = comcat.get_event_by_id(m71_event_id) m71_epoch = time_utils.datetime_to_utc_epoch(event.time) # build aftershock region aftershock_region = regions.generate_aftershock_region(event.magnitude, event.longitude, event.latitude) # apply new aftershock region and magnitude of completeness catalog = catalog.filter_spatial(aftershock_region).apply_mct(event.magnitude, m71_epoch) print(catalog) .. rst-class:: sphx-glr-script-out .. code-block:: none Name: None Start Date: 2019-07-06 03:22:35.630000+00:00 End Date: 2019-09-08 14:07:23.350000+00:00 Latitude: (35.448, 36.1823333) Longitude: (-117.8875, -117.2788333) Min Mw: 3.5 Max Mw: 5.5 Event Count: 234 .. GENERATED FROM PYTHON SOURCE LINES 96-100 Write catalog ------------- Use :meth:`csep.core.catalogs.AbstractBaseCatalog.write_ascii` to write the catalog into the comma separated value format. .. GENERATED FROM PYTHON SOURCE LINES 100-101 .. code-block:: Python catalog.write_ascii('2019-11-11-comcat.csv') .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 25.253 seconds) .. _sphx_glr_download_tutorials_catalog_filtering.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: catalog_filtering.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: catalog_filtering.py ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_