Merge branch 'load-data-by-channel-name-example' into 'master'

Load data by channel name example

See merge request !524

examples/open_data_examples/read_data_from_channel_name.py

+#!/usr/bin/env python
+"""
+Tutorial to demonstrates reading and plotting the GraceDB data for GW170608,
+the lightest GWTC-1 BBH event.
+
+This tutorial must be run on a LIGO cluster.
+"""
+
+import bilby
+
+label = 'GW170608'
+outdir = label + '_out'
+# List of detectors involved in the event. GW170608 is pre-August 2017 so only
+# H1 and L1 were involved
+detectors = ['H1', 'L1']
+# Names of the channels and query types to use, and the event GraceDB ID - ref.
+# https://ldas-jobs.ligo.caltech.edu/~eve.chase/monitor/online_pe/C02_clean/
+# C02_HL_Pv2/lalinferencenest/IMRPhenomPv2pseudoFourPN/config.ini
+channel_names = ['H1:DCH-CLEAN_STRAIN_C02', 'L1:DCH-CLEAN_STRAIN_C02']
+gracedb = 'G288686'
+# Duration of data around the event to use
+duration = 16
+# Duration of PSD data
+psd_duration = 1024
+# Minimum frequency and reference frequency
+minimum_frequency = 10  # Hz
+sampling_frequency = 2048.
+
+# Get trigger time
+candidate = bilby.gw.utils.gracedb_to_json(gracedb, outdir=outdir)
+trigger_time = candidate['gpstime']
+gps_start_time = trigger_time + 2. - duration
+
+# Load the PSD data starting after the segment you want to analyze
+psd_start_time = gps_start_time + duration
+
+# Set up interferometer objects from the cache files
+interferometers = bilby.gw.detector.InterferometerList([])
+
+for channel_name in channel_names:
+    interferometer = bilby.gw.detector.load_data_by_channel_name(
+        start_time=gps_start_time, segment_duration=duration,
+        psd_duration=psd_duration, psd_start_time=psd_start_time,
+        channel_name=channel_name, sampling_frequency=sampling_frequency, outdir=outdir)
+    interferometer.minimum_frequency = minimum_frequency
+    interferometers.append(interferometer)
+
+# Plot the strain data
+interferometers.plot_data(outdir=outdir, label=label)