Adds new example for a weak signal follow-up

examples/weak_signal_follow_up.py

+import pyfstat
+
+# Define parameters of the Crab pulsar as an example
+F0 = 30.0
+F1 = -1e-10
+F2 = 0
+Alpha = 5e-3
+Delta = 6e-2
+tref = 362750407.0
+
+# Properties of the GW data
+sqrtSX = 1e-23
+tstart = 1000000000
+duration = 100*86400
+tend = tstart+duration
+
+depth = 50
+
+h0 = sqrtSX / depth
+
+data = pyfstat.Writer(
+    label='depth_{:1.0f}'.format(depth), outdir='data', tref=tref,
+    tstart=tstart, F0=F0, F1=F1, F2=F2, duration=duration, Alpha=Alpha,
+    Delta=Delta, h0=h0, sqrtSX=sqrtSX)
+data.make_data()
+
+# The predicted twoF, given by lalapps_predictFstat can be accessed by
+twoF = data.predict_fstat()
+print 'Predicted twoF value: {}\n'.format(twoF)
+
+# Search
+theta_prior = {'F0': {'type': 'unif', 'lower': F0*(1-1e-4),
+                      'upper': F0*(1+1e-4)},
+               'F1': {'type': 'unif', 'lower': F1*(1+1e-2),
+                      'upper': F1*(1-1e-2)},
+               'F2': F2,
+               'Alpha': {'type': 'unif', 'lower': Alpha-1e-2,
+                         'upper': Alpha+1e-2},
+               'Delta': {'type': 'unif', 'lower': Delta-5e-2,
+                         'upper': Delta+5e-2},
+               }
+
+ntemps = 1
+log10temperature_min = -1
+nwalkers = 100
+run_setup = [(1000, 50),
+             (1000, 30),
+             (1000, 20),
+             (1000, 15),
+             (1000, 10),
+             (1000, 5),
+             (1000, 1),
+             ((1000, 1000), 1, True)]
+
+mcmc = pyfstat.MCMCFollowUpSearch(
+    label='weak_signal_follow_up', outdir='data',
+    sftfilepath='data/*depth*sft', theta_prior=theta_prior, tref=tref,
+    minStartTime=tstart, maxStartTime=tend, nwalkers=nwalkers,
+    ntemps=ntemps, log10temperature_min=log10temperature_min)
+mcmc.run(run_setup)
+mcmc.plot_corner(add_prior=True)
+mcmc.print_summary()
+mcmc.generate_loudest()