Coverage for bilby/gw/sampler/proposal.py: 100%

1import random 

2 

3import numpy as np 

4 

5from ...core.sampler.proposal import JumpProposal 

6 

7 

8class SkyLocationWanderJump(JumpProposal): 

9 """ 

10 Jump proposal for wandering over the sky location. Does a Gaussian step in 

11 RA and DEC depending on the temperature. 

12 """ 

13 

14 def __call__(self, sample, **kwargs): 

15 temperature = 1 / kwargs.get('inverse_temperature', 1.0) 

16 sigma = np.sqrt(temperature) / 2 / np.pi 

17 sample['ra'] += random.gauss(0, sigma) 

18 sample['dec'] += random.gauss(0, sigma) 

19 return super(SkyLocationWanderJump, self).__call__(sample) 

20 

21 

22class CorrelatedPolarisationPhaseJump(JumpProposal): 

23 """ 

24 Correlated polarisation/phase jump proposal. Jumps between degenerate phi/psi regions. 

25 """ 

26 

27 def __call__(self, sample, **kwargs): 

28 alpha = sample['psi'] + sample['phase'] 

29 beta = sample['psi'] - sample['phase'] 

30 

31 draw = random.random() 

32 if draw < 0.5: 

33 alpha = 3.0 * np.pi * random.random() 

34 else: 

35 beta = 3.0 * np.pi * random.random() - 2 * np.pi 

36 sample['psi'] = (alpha + beta) * 0.5 

37 sample['phase'] = (alpha - beta) * 0.5 

38 return super(CorrelatedPolarisationPhaseJump, self).__call__(sample) 

39 

40 

41class PolarisationPhaseJump(JumpProposal): 

42 """ 

43 Correlated polarisation/phase jump proposal. Jumps between degenerate phi/psi regions. 

44 """ 

45 

46 def __call__(self, sample, **kwargs): 

47 sample['phase'] += np.pi 

48 sample['psi'] += np.pi / 2 

49 return super(PolarisationPhaseJump, self).__call__(sample)