def __init__(self,
params,
output_file,
output_extra_params=[],
nlive=None,
num_repeats=None,
do_clustering=None,
read_resume=None,
**kwargs):
super().__init__(**arguments(exclude=['params']))
self.sampled = params.find_sampled()
settings = self.settings = PolyChordSettings(
len(self.sampled), len(self.output_extra_params))
output_file = './' + osp.normpath(output_file)
settings.base_dir = osp.dirname(output_file)
settings.file_root = osp.basename(output_file)
if mpi.is_master() and not osp.exists(self.settings.base_dir):
os.makedirs(self.settings.base_dir)
for k in ['nlive', 'num_repeats', 'do_clustering', 'read_resume']:
v = arguments()[k]
if v is not None:
setattr(settings, k, v)
return result, []
def prior(hypercube):
""" Priors for each parameter. """
theta = [0.0] * nDims
for i, x in enumerate(hypercube):
theta[i] = priordict[parnames[i]].ppf(x)
return theta
# Define PolyChord settings
settings = PolyChordSettings(
nDims,
nDerived,
)
settings.do_clustering = args_params.noclust
settings.nlive = nDims * args_params.nlive
settings.base_dir = base_dir
settings.file_root = 'hd40307_k{}'.format(nplanets) # modelpath[12:-3]
settings.num_repeats = nDims * args_params.nrep
settings.precision_criterion = args_params.prec
settings.read_resume = False
# Change settings if resume is true
if args_params.resume:
settings.read_resume = args_params.resume
settings.base_dir = dirname + prev_run
# Run PolyChord
def initialise(self):
"""Imports the PolyChord sampler and prepares its arguments."""
if not get_mpi_rank(): # rank = 0 (MPI master) or None (no MPI)
self.log.info("Initializing")
# If path not given, try using general path to modules
path_to_installation = get_path_to_installation()
if not self.path and path_to_installation:
self.path = os.path.join(path_to_installation, "code",
pc_repo_name)
if self.path:
if not get_mpi_rank():
self.log.info("Importing *local* PolyChord from " + self.path)
pc_py_path = os.path.join(self.path, "PyPolyChord")
pc_build_path = os.path.join(self.path, "build")
post = next(d for d in os.listdir(pc_build_path)
if d.startswith("lib."))
pc_build_path = os.path.join(pc_build_path, post)
if not os.path.exists(pc_build_path):
self.log.error(
"Either PolyChord is not in the given folder, "
"'%s', or you have not compiled it.", self.path)
raise HandledException
# Inserting the previously found path into the list of import folders
sys.path.insert(0, pc_build_path)
sys.path.insert(0, pc_py_path)
else:
self.log.info("Importing *global* PolyChord.")
try:
import PyPolyChord as PyPolyChord
from PyPolyChord.settings import PolyChordSettings
except ImportError:
self.log.error(
"Couldn't find the PolyChord python interface. "
"Make sure that you have compiled it, and that you either\n"
" (a) specify a path (you didn't) or\n"
" (b) install the Python interface globally with\n"
" '/path/to/PolyChord/python setup.py install --user'")
raise HandledException
self.pc = PyPolyChord
# Prepare arguments and settings
self.nDims = self.prior.d()
self.nDerived = (len(self.parametrization.derived_params()) + 1 +
len(self.likelihood._likelihoods))
self.pc_settings = PolyChordSettings(self.nDims, self.nDerived)
for p in [
"nlive", "num_repeats", "nprior", "do_clustering",
"precision_criterion", "max_ndead", "boost_posterior",
"feedback", "update_files", "posteriors", "equals",
"cluster_posteriors", "write_resume", "read_resume",
"write_stats", "write_live", "write_dead", "base_dir",
"grade_frac", "grade_dims"
]:
v = getattr(self, p)
if v is not None:
setattr(self.pc_settings, p, v)
# Fill the automatic ones
if getattr(self, "feedback", None) is None:
values = {
logging.CRITICAL: 0,
logging.ERROR: 0,
logging.WARNING: 0,
logging.INFO: 1,
logging.DEBUG: 2
}
self.pc_settings.feedback = values[self.log.getEffectiveLevel()]
try:
output_folder = getattr(self.output, "folder")
output_prefix = getattr(self.output, "prefix") or "pc"
except AttributeError:
# dummy output -- no resume!
from tempfile import gettempdir
output_folder = gettempdir()
from random import random
output_prefix = hex(int(random() * 16**6))[2:]
self.pc_settings.read_resume = False
self.pc_settings.base_dir = os.path.join(output_folder,
self.pc_settings.base_dir)
self.pc_settings.file_root = output_prefix
if not get_mpi_rank():
# Creating output folder, if it does not exist (just one process)
if not os.path.exists(self.pc_settings.base_dir):
os.makedirs(self.pc_settings.base_dir)
# Idem, a clusters folder if needed -- notice that PolyChord's default
# is "True", here "None", hence the funny condition below
if self.pc_settings.do_clustering is not False: # None here means "default"
try:
os.makedirs(
os.path.join(self.pc_settings.base_dir, clusters))
except OSError: # exists!
pass
self.log.info("Storing raw PolyChord output in '%s'.",
self.pc_settings.base_dir)
# explotining the speed hierarchy
# sort blocks by paramters order and check contiguity (required by PolyChord!!!)
# speeds, blocks = zip(*self.likelihood.speed_blocked_params(as_indices=True))
# speeds, blocks = np.array(speeds), np.array(blocks)
# weird behaviour of np.argsort with there is only 1 block
# if len(blocks) > 1:
# sorting_indices = np.argsort(blocks, axis=0)
# else:
# sorting_indices = [0]
# speeds, blocks = speeds[sorting_indices], blocks[sorting_indices]
# if np.all([np.all(block==range(block[0], block[-1]+1)) for block in blocks]):
self.log.warning("Speed hierarchy exploitation disabled for now!")
# self.pc_args["grade_frac"] = list(speeds)
# self.pc_args["grade_dims"] = [len(block) for block in blocks]
# self.log.info("Exploiting a speed hierarchy with speeds %r and blocks %r",
# speeds, blocks)
# else:
# self.log.warning("Some speed blocks are not contiguous: PolyChord cannot deal "
# "with the speed hierarchy. Not exploting it.")
# prior conversion from the hypercube
bounds = self.prior.bounds(
confidence_for_unbounded=self.confidence_for_unbounded)
# Check if priors are bounded (nan's to inf)
inf = np.where(np.isinf(bounds))
if len(inf[0]):
params_names = self.prior.names()
params = [params_names[i] for i in sorted(list(set(inf[0])))]
self.log.error(
"PolyChord needs bounded priors, but the parameter(s) '"
"', '".join(params) + "' is(are) unbounded.")
raise HandledException
locs = bounds[:, 0]
scales = bounds[:, 1] - bounds[:, 0]
self.pc_prior = lambda x: (locs + np.array(x) * scales).tolist()
# We will need the volume of the prior domain, since PolyChord divides by it
self.logvolume = np.log(np.prod(scales))
# Done!
if not get_mpi_rank():
self.log.info("Calling PolyChord with arguments:")
for p, v in inspect.getmembers(self.pc_settings,
lambda a: not (callable(a))):
if not p.startswith("_"):
self.log.info(" %s: %s", p, v)
def PolyChordrun(LogLikelihood,n_dims,n_params,**kwargs):
"""
Function author: yuanfang
PolyChord settings
For full details of nested sampling and PolyChord, please refer to:
arxiv:1506.00171[astro-ph.IM], 0809.34371[astro-ph]
Parameters
----------
nDims: int
Dimensionality of the model, i.e. the number of physical parameters.
nDerived: int
The number of derived parameters (can be 0).
Keyword arguments
-----------------
nlive: int
(Default: nDims*25)
The number of live points.
Increasing nlive increases the accuracy of posteriors and evidences,
and proportionally increases runtime ~ O(nlive).
num_repeats : int
(Default: nDims*5)
The number of slice slice-sampling steps to generate a new point.
Increasing num_repeats increases the reliability of the algorithm.
Typically
* for reliable evidences need num_repeats ~ O(5*nDims).
* for reliable posteriors need num_repeats ~ O(nDims)
nprior : int
(Default: nlive)
The number of prior samples to draw before starting compression.
do_clustering : boolean
(Default: True)
Whether or not to use clustering at run time.
feedback : {0,1,2,3}
(Default: 1)
How much command line feedback to give
# Degree of feedback to provide
#-1 | nothing
# 0 | just header and tail
# 1 | run time evidences and clustering information
# 2 | fancy output
# 3 | verbose
precision_criterion : float
(Default: 0.001)
Termination criterion. Nested sampling terminates when the evidence
contained in the live points is precision_criterion fraction of the
total evidence.
max_ndead : int
(Default: -1)
Alternative termination criterion. Stop after max_ndead iterations.
Set negative to ignore (default).
boost_posterior : float
(Default: 0.0)
Increase the number of posterior samples produced. This can be set
arbitrarily high, but you won't be able to boost by more than
num_repeats
Warning: in high dimensions PolyChord produces _a lot_ of posterior
samples. You probably don't need to change this
posteriors : boolean
(Default: True)
Produce (weighted) posterior samples. Stored in <root>.txt.
equals : boolean
(Default: True)
Produce (equally weighted) posterior samples. Stored in
<root>_equal_weights.txt
cluster_posteriors : boolean
(Default: True)
Produce posterior files for each cluster?
Does nothing if do_clustering=False.
write_resume : boolean
(Default: True)
Create a resume file.
read_resume : boolean
(Default: True)
Read from resume file.
write_stats : boolean
(Default: True)
Write an evidence statistics file.
write_live : boolean
(Default: True)
Write a live points file.
write_dead : boolean
(Default: True)
Write a dead points file.
write_dead : boolean
(Default: True)
Write a prior points file.
update_files : int
(Default: nlive)
How often to update the files in <base_dir>.
base_dir : string
(Default: 'chains')
Where to store output files.
file_root : string
(Default: 'test')
Root name of the files produced.
grade_frac : List[float]
(Default: 1)
The amount of time to spend in each speed.
grade_dims : List[int]
(Default: 1)
The number of parameters within each speed.
"""
try:
import math
from numpy import pi, log, sqrt
import PyPolyChord
from PyPolyChord.settings import PolyChordSettings
from PyPolyChord.priors import UniformPrior
except ImportError:
print("INFO(Scanner):PyPolyChord module import error.exit...")
sys.exit()
# pass settings to polychord
nDerived=n_params-n_dims
settings = PolyChordSettings(n_dims, nDerived)
# settings.nlive = kwargs.pop('nlive', n_dims*25)
settings.nlive = kwargs.pop('n_live_points', n_dims*25)
# settings.num_repeats = kwargs.pop('num_repeats', n_dims*5)
settings.num_repeats = kwargs.pop('num_repeats', n_dims*2) # proposed by polychord eggbox
settings.nprior = kwargs.pop('nprior', -1)
settings.do_clustering = kwargs.pop('do_clustering', True)
settings.feedback = kwargs.pop('feedback', 1)
settings.precision_criterion = kwargs.pop('precision_criterion', 0.001)
settings.max_ndead = kwargs.pop('max_ndead', -1)
settings.boost_posterior = kwargs.pop('boost_posterior', 0.0)
settings.posteriors = kwargs.pop('posteriors', True)
settings.equals = kwargs.pop('equals', True)
settings.cluster_posteriors = kwargs.pop('cluster_posteriors', True)
settings.write_resume = kwargs.pop('write_resume', True)
settings.write_paramnames = kwargs.pop('write_paramnames', False)
settings.read_resume = kwargs.pop('read_resume', True)
settings.write_stats = kwargs.pop('write_stats', True)
settings.write_live = kwargs.pop('write_live', True)
settings.write_dead = kwargs.pop('write_dead', True)
settings.write_prior = kwargs.pop('write_prior', True)
settings.update_files = kwargs.pop('update_files', settings.nlive)
settings.base_dir = kwargs.pop('base_dir', 'chains')
settings.file_root = kwargs.pop('file_root', 'test')
settings.grade_dims = kwargs.pop('grade_dims', [n_dims])
settings.max_ndead=kwargs.pop('max_ndead ',-1)
ES=kwargs.pop('ES')
# settings.grade_frac = kwargs.pop('grade_frac', [1.0]*len(self.grade_dims))
if kwargs:
raise TypeError('Unexpected **kwargs in Contours constructor: %r' % kwargs)
# to speed up, set do_clustring = false
# settings.do_clustering=False
def my_prior(hypercube):
'''
theta: the hypercube for input parameters
len(theta)=n_dims
Get the phiscal parameters from hypercube
'''
theta=[0.0]*n_dims
for i,name in enumerate(ES.InPar):
if ES.InputPar[name][1].lower() == 'flat':
min = float(ES.InputPar[name][2])
max = float(ES.InputPar[name][3])
theta[i] = hypercube[i] * (max - min) + min
elif ES.InputPar[name][1].lower() == 'log':
min = math.log10(float(ES.InputPar[name][2]))
max = math.log10(float(ES.InputPar[name][3]))
theta[i] = 10.0**(hypercube[i]*(max - min) + min )
else:
sf.ErrorStop( 'Not ready. Only "flat" and "log" prior can be used.' )
# print 'my_prior: theta=',theta
return theta
def my_Loglikelihood(theta):
phi=[0.0]*nDerived
derived=[0.0]*nDerived
theta.extend(derived)
cube=theta
logL=LogLikelihood(cube,n_dims,n_params)
# print 'my_Loglikelihood after log',cube
phi=cube[n_dims:]
# print 'my loglikelihood: phi=',phi
# print 'my log likelihood: LogL=',logL
return logL,phi
output = PyPolyChord.run_polychord(my_Loglikelihood, n_dims, nDerived, settings, my_prior)