adding damped sinusoid time domain example

examples/injection_examples/create_your_own_time_domain_source_model.py

+"""
+A script to show how to create your own time domain source model.
+A simple damped Gaussian signal is defined in the time domain, injected into noise in
+two interferometers (LIGO Livingston and Hanford at design sensitivity),
+and then recovered.
+"""
+
+import tupak
+import numpy as np
+
+tupak.utils.setup_logger()
+
+
+# define the time-domain model
+def time_domain_damped_sinusoid(time, amplitude, damping_time, frequency, phase, ra, dec, psi, geocent_time):
+    """
+    This example only creates a linearly polarised signal with only plus polarisation.
+    """
+
+    plus = amplitude * np.exp(-time / damping_time) * np.sin(2.*np.pi*frequency*time + phase)
+    cross = np.zeros(len(time))
+
+    return {'plus': plus, 'cross': cross}
+
+# define parameters to inject.
+injection_parameters = dict(amplitude=5e-22, damping_time=0.1, frequency=50,
+                            phase=0,
+                            ra=0, dec=0, psi=0, geocent_time=0.)
+
+time_duration = 0.5
+sampling_frequency = 2048
+outdir='outdir'
+label='time_domain_source_model'
+
+# call the waveform_generator to create our waveform model.
+waveform = tupak.waveform_generator.WaveformGenerator(time_duration=time_duration, sampling_frequency=sampling_frequency,
+                                                    time_domain_source_model=time_domain_damped_sinusoid,
+                                                    parameters=injection_parameters)
+
+hf_signal = waveform.frequency_domain_strain()
+#note we could plot the time domain signal with the following code
+# import matplotlib.pyplot as plt
+# plt.plot(waveform.time_array, waveform.time_domain_strain()['plus'])
+
+# or the frequency-domain signal:
+# plt.loglog(waveform.frequency_array, abs(waveform.frequency_domain_strain()['plus']))
+
+
+
+# inject the signal into three interferometers
+IFOs = [tupak.detector.get_interferometer_with_fake_noise_and_injection(
+        name, injection_polarizations=hf_signal,
+        injection_parameters=injection_parameters, time_duration=time_duration,
+        sampling_frequency=sampling_frequency, outdir=outdir)
+        for name in ['H1', 'L1']]
+
+
+#  create the priors
+prior = injection_parameters.copy()
+prior['amplitude'] = tupak.prior.Uniform(1e-23, 1e-21, r'$h_0$')
+prior['damping_time'] = tupak.prior.Uniform(0, 1, r'damping time')
+prior['frequency'] = tupak.prior.Uniform(0, 200, r'frequency')
+prior['phase'] = tupak.prior.Uniform(-np.pi/2, np.pi/2, r'$\phi$')
+
+
+# define likelihood
+likelihood = tupak.likelihood.Likelihood(IFOs, waveform)
+
+# launch sampler
+result = tupak.sampler.run_sampler(likelihood, prior, sampler='dynesty', npoints=1000,
+                                    injection_parameters=injection_parameters,
+                                    outdir=outdir, label=label)
+
+result.plot_walks()
+result.plot_distributions()
+result.plot_corner()
+
+print(result)