def load_collections(self,
model,
skip=0,
thin=1,
concatenate=False,
name=None,
extension=None):
"""
Loads all collection files found which are compatible with this `Output`
instance, including their path in their name.
Use `name` for particular types of collections (default: any number).
Pass `False` to mean there is nothing between the output prefix and the extension.
"""
filenames = self.find_collections(name=name, extension=extension)
collections = [
Collection(model,
self,
name="%d" % (1 + i),
file_name=filename,
load=True,
onload_skip=skip,
onload_thin=thin)
for i, filename in enumerate(filenames)
]
if concatenate and collections:
collection = collections[0]
for collection_i in collections[1:]:
collection.append(collection_i)
collections = collection
return collections
def initialise(self):
"""
Creates a 1-point collection to store the point
at which the posterior is evaluated.
"""
self.one_point = Collection(self.parametrization, self.likelihood,
self.output, initial_size=1, name="1")
self.log.info("Initialised!")
def initialize(self):
"""
Creates a 1-point collection to store the point
at which the posterior is evaluated.
"""
self.one_point = Collection(self.model,
self.output,
initial_size=1,
name="1")
self.log.info("Initialized!")
def initialize(self):
self.log.info("Initializing.")
# Example for setting default options
print("+++ For option '%s' got value '%s'. Add more options in fisher.yaml." % (
"example_option", self.example_option))
# Prepare the list of "samples" (posterior evaluations)
self.collection = Collection(self.model, self.output)
# Prepare vectors to store derivatives
# ... up to you
# Prepare the matrix
self.fisher_matrix = np.eye(self.model.prior.d())
def load_collections(self, model, skip=0, thin=1, concatenate=False):
filenames = self.find_collections()
collections = [
Collection(model, self, name="%d" % (1 + i), file_name=filename,
load=True, onload_skip=skip, onload_thin=thin)
for i, filename in enumerate(filenames)]
if concatenate and collections:
collection = collections[0]
for collection_i in collections[1:]:
collection._append(collection_i)
collections = collection
return collections
def initialize(self):
"""
Creates a 1-point collection to store the point
at which the posterior is evaluated.
"""
try:
self.N = int(self.N)
except:
raise LoggedError(
self.log,
"Could not convert the number of samples to an integer: %r", self.N)
self.one_point = Collection(
self.model, self.output, initial_size=self.N, name="1")
self.log.info("Initialized!")
def save_sample(self, fname, name):
sample = np.atleast_2d(np.loadtxt(fname))
if not sample.size:
return None
collection = Collection(self.model, self.output, name=str(name))
for row in sample:
collection.add(
row[2:2 + self.n_sampled],
derived=row[2 + self.n_sampled:2 + self.n_sampled + self.n_derived + 1],
weight=row[0], logpost=-row[1],
logpriors=row[-(self.n_priors + self.n_likes):-self.n_likes],
loglikes=row[-self.n_likes:])
# make sure that the points are written
collection._out_update()
return collection
def save_sample(self, fname, name):
sample = np.atleast_2d(np.loadtxt(fname))
collection = Collection(self.parametrization,
self.likelihood,
self.output,
name=str(name))
for row in sample:
collection.add(row[2:2 + self.n_sampled],
derived=row[2 + self.n_sampled:2 + self.n_sampled +
self.n_derived + 1],
weight=row[0],
logpost=-row[1],
logprior=row[-(1 + self.n_liks)],
logliks=row[-self.n_liks:])
# make sure that the points are written
collection.out_update()
return collection
def initialize(self):
"""Imports the PolyChord sampler and prepares its arguments."""
# Allow global import if no direct path specification
allow_global = not self.path
if not self.path and self.packages_path:
self.path = self.get_path(self.packages_path)
self.pc = self.is_installed(path=self.path, allow_global=allow_global)
if not self.pc:
raise NotInstalledError(
self.log,
"Could not find PolyChord. Check error message above. "
"To install it, run 'cobaya-install polychord --%s "
"[packages_path]'", _packages_path_arg)
# Prepare arguments and settings
from pypolychord.settings import PolyChordSettings
self.n_sampled = len(self.model.parameterization.sampled_params())
self.n_derived = len(self.model.parameterization.derived_params())
self.n_priors = len(self.model.prior)
self.n_likes = len(self.model.likelihood)
self.nDims = self.model.prior.d()
self.nDerived = (self.n_derived + self.n_priors + self.n_likes)
if self.logzero is None:
self.logzero = np.nan_to_num(-np.inf)
if self.max_ndead == np.inf:
self.max_ndead = -1
self._quants_d_units = ["nlive", "max_ndead"]
for p in self._quants_d_units:
if getattr(self, p) is not None:
setattr(
self, p,
NumberWithUnits(getattr(self, p),
"d",
scale=self.nDims,
dtype=int).value)
self._quants_nlive_units = ["nprior"]
for p in self._quants_nlive_units:
if getattr(self, p) is not None:
setattr(
self, p,
NumberWithUnits(getattr(self, p),
"nlive",
scale=self.nlive,
dtype=int).value)
# 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.feedback = values[self.log.getEffectiveLevel()]
# Prepare output folders and prefixes
if self.output:
self.file_root = self.output.prefix
self.read_resume = self.output.is_resuming()
else:
output_prefix = share_mpi(
hex(int(random() * 16**6))[2:] if is_main_process() else None)
self.file_root = output_prefix
# dummy output -- no resume!
self.read_resume = False
self.base_dir = self.get_base_dir(self.output)
self.raw_clusters_dir = os.path.join(self.base_dir, self._clusters_dir)
self.output.create_folder(self.base_dir)
if self.do_clustering:
self.clusters_folder = self.get_clusters_dir(self.output)
self.output.create_folder(self.clusters_folder)
self.mpi_info("Storing raw PolyChord output in '%s'.", self.base_dir)
# Exploiting the speed hierarchy
if self.blocking:
blocks, oversampling_factors = self.model.check_blocking(
self.blocking)
else:
if self.measure_speeds:
self.model.measure_and_set_speeds(n=self.measure_speeds)
blocks, oversampling_factors = self.model.get_param_blocking_for_sampler(
oversample_power=self.oversample_power)
self.mpi_info("Parameter blocks and their oversampling factors:")
max_width = len(str(max(oversampling_factors)))
for f, b in zip(oversampling_factors, blocks):
self.mpi_info("* %" + "%d" % max_width + "d : %r", f, b)
# Save blocking in updated info, in case we want to resume
self._updated_info["blocking"] = list(zip(oversampling_factors,
blocks))
blocks_flat = list(chain(*blocks))
self.ordering = [
blocks_flat.index(p)
for p in self.model.parameterization.sampled_params()
]
self.grade_dims = [len(block) for block in blocks]
# Steps per block
# NB: num_repeats is ignored by PolyChord when int "grade_frac" given,
# so needs to be applied by hand.
# In num_repeats, `d` is interpreted as dimension of each block
self.grade_frac = [
int(o * read_dnumber(self.num_repeats, dim_block))
for o, dim_block in zip(oversampling_factors, self.grade_dims)
]
# Assign settings
pc_args = [
"nlive", "num_repeats", "nprior", "do_clustering",
"precision_criterion", "max_ndead", "boost_posterior", "feedback",
"logzero", "posteriors", "equals", "compression_factor",
"cluster_posteriors", "write_resume", "read_resume", "write_stats",
"write_live", "write_dead", "base_dir", "grade_frac", "grade_dims",
"feedback", "read_resume", "base_dir", "file_root", "grade_frac",
"grade_dims"
]
# As stated above, num_repeats is ignored, so let's not pass it
pc_args.pop(pc_args.index("num_repeats"))
self.pc_settings = PolyChordSettings(
self.nDims,
self.nDerived,
seed=(self.seed if self.seed is not None else -1),
**{
p: getattr(self, p)
for p in pc_args if getattr(self, p) is not None
})
# prior conversion from the hypercube
bounds = self.model.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.model.parameterization.sampled_params()
params = [params_names[i] for i in sorted(list(set(inf[0])))]
raise LoggedError(
self.log,
"PolyChord needs bounded priors, but the parameter(s) '"
"', '".join(params) + "' is(are) unbounded.")
locs = bounds[:, 0]
scales = bounds[:, 1] - bounds[:, 0]
# This function re-scales the parameters AND puts them in the right order
self.pc_prior = lambda x: (locs + np.array(x)[self.ordering] * scales
).tolist()
# We will need the volume of the prior domain, since PolyChord divides by it
self.logvolume = np.log(np.prod(scales))
# Prepare callback function
if self.callback_function is not None:
self.callback_function_callable = (get_external_function(
self.callback_function))
self.last_point_callback = 0
# Prepare runtime live and dead points collections
self.live = Collection(self.model,
None,
name="live",
initial_size=self.pc_settings.nlive)
self.dead = Collection(self.model, self.output, name="dead")
# Done!
if is_main_process():
self.log.debug("Calling PolyChord with arguments:")
for p, v in inspect.getmembers(self.pc_settings,
lambda a: not (callable(a))):
if not p.startswith("_"):
self.log.debug(" %s: %s", p, v)
self.mpi_info("Initialized!")
def post(info, sample=None):
logger_setup(info.get(_debug), info.get(_debug_file))
log = logging.getLogger(__name__.split(".")[-1])
# MARKED FOR DEPRECATION IN v3.0
# BEHAVIOUR TO BE REPLACED BY ERROR:
check_deprecated_modules_path(info)
# END OF DEPRECATION BLOCK
try:
info_post = info[_post]
except KeyError:
raise LoggedError(log, "No 'post' block given. Nothing to do!")
if get_mpi_rank():
log.warning(
"Post-processing is not yet MPI-aware. Doing nothing for rank > 1 processes.")
return
if info.get(_resume):
log.warning("Resuming not implemented for post-processing. Re-starting.")
# 1. Load existing sample
output_in = get_output(output_prefix=info.get(_output_prefix))
if output_in:
try:
info_in = output_in.reload_updated_info()
except FileNotFoundError:
raise LoggedError(log, "Error loading input model: "
"could not find input info at %s",
output_in.file_updated)
else:
info_in = deepcopy_where_possible(info)
dummy_model_in = DummyModel(info_in[_params], info_in[kinds.likelihood],
info_in.get(_prior, None))
if output_in:
if not output_in.find_collections():
raise LoggedError(log, "No samples found for the input model with prefix %s",
os.path.join(output_in.folder, output_in.prefix))
collection_in = output_in.load_collections(
dummy_model_in, skip=info_post.get("skip", 0), thin=info_post.get("thin", 1),
concatenate=True)
elif sample:
if isinstance(sample, Collection):
sample = [sample]
collection_in = deepcopy(sample[0])
for s in sample[1:]:
try:
collection_in.append(s)
except:
raise LoggedError(log, "Failed to load some of the input samples.")
else:
raise LoggedError(log,
"Not output from where to load from or input collections given.")
log.info("Will process %d samples.", len(collection_in))
if len(collection_in) <= 1:
raise LoggedError(
log, "Not enough samples for post-processing. Try using a larger sample, "
"or skipping or thinning less.")
# 2. Compare old and new info: determine what to do
add = info_post.get(_post_add, {}) or {}
remove = info_post.get(_post_remove, {})
# Add a dummy 'one' likelihood, to absorb unused parameters
if not add.get(kinds.likelihood):
add[kinds.likelihood] = {}
add[kinds.likelihood]["one"] = None
# Expand the "add" info
add = update_info(add)
# 2.1 Adding/removing derived parameters and changes in priors of sampled parameters
out = {_params: deepcopy_where_possible(info_in[_params])}
for p in remove.get(_params, {}):
pinfo = info_in[_params].get(p)
if pinfo is None or not is_derived_param(pinfo):
raise LoggedError(
log,
"You tried to remove parameter '%s', which is not a derived parameter. "
"Only derived parameters can be removed during post-processing.", p)
out[_params].pop(p)
# Force recomputation of aggregated chi2
for p in list(out[_params]):
if p.startswith(_get_chi2_name("")):
out[_params].pop(p)
mlprior_names_add = []
for p, pinfo in add.get(_params, {}).items():
pinfo_in = info_in[_params].get(p)
if is_sampled_param(pinfo):
if not is_sampled_param(pinfo_in):
# No added sampled parameters (de-marginalisation not implemented)
if pinfo_in is None:
raise LoggedError(
log, "You added a new sampled parameter %r (maybe accidentally "
"by adding a new likelihood that depends on it). "
"Adding new sampled parameters is not possible. Try fixing "
"it to some value.", p)
else:
raise LoggedError(
log,
"You tried to change the prior of parameter '%s', "
"but it was not a sampled parameter. "
"To change that prior, you need to define as an external one.", p)
if mlprior_names_add[:1] != _prior_1d_name:
mlprior_names_add = ([_minuslogprior + _separator + _prior_1d_name]
+ mlprior_names_add)
elif is_derived_param(pinfo):
if p in out[_params]:
raise LoggedError(
log, "You tried to add derived parameter '%s', which is already "
"present. To force its recomputation, 'remove' it too.", p)
elif is_fixed_param(pinfo):
# Only one possibility left "fixed" parameter that was not present before:
# input of new likelihood, or just an argument for dynamical derived (dropped)
if ((p in info_in[_params] and
pinfo[partag.value] != (pinfo_in or {}).get(partag.value, None))):
raise LoggedError(
log,
"You tried to add a fixed parameter '%s: %r' that was already present"
" but had a different value or was not fixed. This is not allowed. "
"The old info of the parameter was '%s: %r'",
p, dict(pinfo), p, dict(pinfo_in))
else:
raise LoggedError(log, "This should not happen. Contact the developers.")
out[_params][p] = pinfo
# For the likelihood only, turn the rest of *derived* parameters into constants,
# so that the likelihoods do not try to compute them)
# But be careful to exclude *input* params that have a "derived: True" value
# (which in "updated info" turns into "derived: 'lambda [x]: [x]'")
out_params_like = deepcopy_where_possible(out[_params])
for p, pinfo in out_params_like.items():
if ((is_derived_param(pinfo) and not (partag.value in pinfo)
and p not in add.get(_params, {}))):
out_params_like[p] = {partag.value: np.nan, partag.drop: True}
# 2.2 Manage adding/removing priors and likelihoods
warn_remove = False
for level in [_prior, kinds.likelihood]:
out[level] = getattr(dummy_model_in, level)
if level == _prior:
out[level].remove(_prior_1d_name)
for pdf in info_post.get(_post_remove, {}).get(level, []) or []:
try:
out[level].remove(pdf)
warn_remove = True
except ValueError:
raise LoggedError(
log, "Trying to remove %s '%s', but it is not present. "
"Existing ones: %r", level, pdf, out[level])
if warn_remove:
log.warning("You are removing a prior or likelihood pdf. "
"Notice that if the resulting posterior is much wider "
"than the original one, or displaced enough, "
"it is probably safer to explore it directly.")
if _prior in add:
mlprior_names_add += [_minuslogprior + _separator + name for name in add[_prior]]
out[_prior] += list(add[_prior])
prior_recompute_1d = (
mlprior_names_add[:1] == [_minuslogprior + _separator + _prior_1d_name])
# Don't initialise the theory code if not adding/recomputing theory,
# theory-derived params or likelihoods
recompute_theory = info_in.get(kinds.theory) and not (
list(add[kinds.likelihood]) == ["one"] and
not any(is_derived_param(pinfo) for pinfo in add.get(_params, {}).values()))
if recompute_theory:
# Inherit from the original chain (needs input|output_params, renames, etc
add_theory = add.get(kinds.theory)
if add_theory:
info_theory_out = {}
if len(add_theory) > 1:
log.warning('Importance sampling with more than one theory is '
'not really tested')
add_theory = add_theory.copy()
for theory, theory_info in info_in[kinds.theory].items():
theory_copy = deepcopy_where_possible(theory_info)
if theory in add_theory:
info_theory_out[theory] = \
recursive_update(theory_copy, add_theory.pop(theory))
else:
info_theory_out[theory] = theory_copy
info_theory_out.update(add_theory)
else:
info_theory_out = deepcopy_where_possible(info_in[kinds.theory])
else:
info_theory_out = None
chi2_names_add = [
_get_chi2_name(name) for name in add[kinds.likelihood] if name != "one"]
out[kinds.likelihood] += [l for l in add[kinds.likelihood] if l != "one"]
if recompute_theory:
log.warning("You are recomputing the theory, but in the current version this does"
" not force recomputation of any likelihood or derived parameter, "
"unless explicitly removed+added.")
for level in [_prior, kinds.likelihood]:
for i, x_i in enumerate(out[level]):
if x_i in list(out[level])[i + 1:]:
raise LoggedError(
log, "You have added %s '%s', which was already present. If you "
"want to force its recomputation, you must also 'remove' it.",
level, x_i)
# 3. Create output collection
if _post_suffix not in info_post:
raise LoggedError(log, "You need to provide a '%s' for your chains.",
_post_suffix)
# Use default prefix if it exists. If it does not, produce no output by default.
# {post: {output: None}} suppresses output, and if it's a string, updates it.
out_prefix = info_post.get(_output_prefix, info.get(_output_prefix))
if out_prefix not in [None, False]:
out_prefix += _separator_files + _post + _separator_files + info_post[
_post_suffix]
output_out = get_output(output_prefix=out_prefix, force=info.get(_force))
if output_out and not output_out.force and output_out.find_collections():
raise LoggedError(log, "Found existing post-processing output with prefix %r. "
"Delete it manually or re-run with `force: True` "
"(or `-f`, `--force` from the shell).", out_prefix)
elif output_out and output_out.force:
output_out.delete_infos()
for regexp in output_out.find_collections():
output_out.delete_with_regexp(re.compile(regexp))
info_out = deepcopy_where_possible(info)
info_out[_post] = info_post
# Updated with input info and extended (updated) add info
info_out.update(info_in)
info_out[_post][_post_add] = add
dummy_model_out = DummyModel(out[_params], out[kinds.likelihood],
info_prior=out[_prior])
if recompute_theory:
# TODO: May need updating for more than one, or maybe can be removed
theory = list(info_theory_out)[0]
if _input_params not in info_theory_out[theory]:
raise LoggedError(
log,
"You appear to be post-processing a chain generated with an older "
"version of Cobaya. For post-processing to work, please edit the "
"'[root].updated.yaml' file of the original chain to add, inside the "
"theory code block, the list of its input parameters. E.g.\n----\n"
"theory:\n %s:\n input_params: [param1, param2, ...]\n"
"----\nIf you get strange errors later, it is likely that you did not "
"specify the correct set of theory parameters.\n"
"The full set of input parameters are %s.",
theory, list(dummy_model_out.parameterization.input_params()))
# TODO: check allow_renames=False?
# TODO: May well be simplifications here, this is v close to pre-refactor logic
# Have not gone through or understood all the parameterization stuff
model_add = Model(out_params_like, add[kinds.likelihood], info_prior=add.get(_prior),
info_theory=info_theory_out, packages_path=info.get(_packages_path),
allow_renames=False, post=True,
prior_parameterization=dummy_model_out.parameterization)
# Remove auxiliary "one" before dumping -- 'add' *is* info_out[_post][_post_add]
add[kinds.likelihood].pop("one")
collection_out = Collection(dummy_model_out, output_out, name="1")
output_out.check_and_dump_info(None, info_out, check_compatible=False)
# Prepare recomputation of aggregated chi2
# (they need to be recomputed by hand, because its autocomputation won't pick up
# old likelihoods for a given type)
all_types = {
like: str_to_list(add[kinds.likelihood].get(
like, info_in[kinds.likelihood].get(like)).get("type", []) or [])
for like in out[kinds.likelihood]}
types = set(chain(*list(all_types.values())))
inv_types = {t: [like for like, like_types in all_types.items() if t in like_types]
for t in types}
# 4. Main loop!
log.info("Running post-processing...")
last_percent = 0
for i, point in collection_in.data.iterrows():
log.debug("Point: %r", point)
sampled = [point[param] for param in
dummy_model_in.parameterization.sampled_params()]
derived = {param: point.get(param, None)
for param in dummy_model_out.parameterization.derived_params()}
inputs = {param: point.get(
param, dummy_model_in.parameterization.constant_params().get(
param, dummy_model_out.parameterization.constant_params().get(
param, None)))
for param in dummy_model_out.parameterization.input_params()}
# Solve inputs that depend on a function and were not saved
# (we don't use the Parameterization_to_input method in case there are references
# to functions that cannot be loaded at the moment)
for p, value in inputs.items():
if value is None:
func = dummy_model_out.parameterization._input_funcs[p]
args = dummy_model_out.parameterization._input_args[p]
inputs[p] = func(*[point.get(arg) for arg in args])
# Add/remove priors
priors_add = model_add.prior.logps(sampled)
if not prior_recompute_1d:
priors_add = priors_add[1:]
logpriors_add = dict(zip(mlprior_names_add, priors_add))
logpriors_new = [logpriors_add.get(name, - point.get(name, 0))
for name in collection_out.minuslogprior_names]
if log.getEffectiveLevel() <= logging.DEBUG:
log.debug(
"New set of priors: %r", dict(zip(dummy_model_out.prior, logpriors_new)))
if -np.inf in logpriors_new:
continue
# Add/remove likelihoods
output_like = []
if add[kinds.likelihood]:
# Notice "one" (last in likelihood_add) is ignored: not in chi2_names
loglikes_add, output_like = model_add.logps(inputs, return_derived=True)
loglikes_add = dict(zip(chi2_names_add, loglikes_add))
output_like = dict(zip(model_add.output_params, output_like))
else:
loglikes_add = dict()
loglikes_new = [loglikes_add.get(name, -0.5 * point.get(name, 0))
for name in collection_out.chi2_names]
if log.getEffectiveLevel() <= logging.DEBUG:
log.debug(
"New set of likelihoods: %r",
dict(zip(dummy_model_out.likelihood, loglikes_new)))
if output_like:
log.debug("New set of likelihood-derived parameters: %r", output_like)
if -np.inf in loglikes_new:
continue
# Add/remove derived parameters and change priors of sampled parameters
for p in add[_params]:
if p in dummy_model_out.parameterization._directly_output:
derived[p] = output_like[p]
elif p in dummy_model_out.parameterization._derived_funcs:
func = dummy_model_out.parameterization._derived_funcs[p]
args = dummy_model_out.parameterization._derived_args[p]
derived[p] = func(
*[point.get(arg, output_like.get(arg, None)) for arg in args])
# We need to recompute the aggregated chi2 by hand
for type_, likes in inv_types.items():
derived[_get_chi2_name(type_)] = sum(
[-2 * lvalue for lname, lvalue
in zip(collection_out.chi2_names, loglikes_new)
if _undo_chi2_name(lname) in likes])
if log.getEffectiveLevel() <= logging.DEBUG:
log.debug("New derived parameters: %r",
dict([(p, derived[p])
for p in dummy_model_out.parameterization.derived_params()
if p in add[_params]]))
# Save to the collection (keep old weight for now)
collection_out.add(
sampled, derived=derived.values(), weight=point.get(_weight),
logpriors=logpriors_new, loglikes=loglikes_new)
# Display progress
percent = np.round(i / len(collection_in) * 100)
if percent != last_percent and not percent % 5:
last_percent = percent
progress_bar(log, percent, " (%d/%d)" % (i, len(collection_in)))
if not collection_out.data.last_valid_index():
raise LoggedError(
log, "No elements in the final sample. Possible causes: "
"added a prior or likelihood valued zero over the full sampled domain, "
"or the computation of the theory failed everywhere, etc.")
# Reweight -- account for large dynamic range!
# Prefer to rescale +inf to finite, and ignore final points with -inf.
# Remove -inf's (0-weight), and correct indices
difflogmax = max(collection_in[_minuslogpost] - collection_out[_minuslogpost])
collection_out.data[_weight] *= np.exp(
collection_in[_minuslogpost] - collection_out[_minuslogpost] - difflogmax)
collection_out.data = (
collection_out.data[collection_out.data.weight > 0].reset_index(drop=True))
collection_out._n = collection_out.data.last_valid_index() + 1
# Write!
collection_out.out_update()
log.info("Finished! Final number of samples: %d", len(collection_out))
return info_out, {"sample": collection_out}
def initialize(self):
self.mpi_info("Initializing")
self.max_evals = read_dnumber(self.max_evals, self.model.prior.d())
# Configure target
method = self.model.loglike if self.ignore_prior else self.model.logpost
kwargs = {"make_finite": True}
if self.ignore_prior:
kwargs["return_derived"] = False
self.logp = lambda x: method(x, **kwargs)
# Try to load info from previous samples.
# If none, sample from reference (make sure that it has finite like/post)
initial_point = None
if self.output:
files = self.output.find_collections()
collection_in = None
if files:
if more_than_one_process():
if 1 + get_mpi_rank() <= len(files):
collection_in = Collection(self.model,
self.output,
name=str(1 +
get_mpi_rank()),
resuming=True)
else:
collection_in = self.output.load_collections(
self.model, concatenate=True)
if collection_in:
initial_point = (collection_in.bestfit()
if self.ignore_prior else collection_in.MAP())
initial_point = initial_point[list(
self.model.parameterization.sampled_params())].values
self.log.info("Starting from %s of previous chain:",
"best fit" if self.ignore_prior else "MAP")
if initial_point is None:
this_logp = -np.inf
while not np.isfinite(this_logp):
initial_point = self.model.prior.reference()
this_logp = self.logp(initial_point)
self.log.info("Starting from random initial point:")
self.log.info(
dict(
zip(self.model.parameterization.sampled_params(),
initial_point)))
self._bounds = self.model.prior.bounds(
confidence_for_unbounded=self.confidence_for_unbounded)
# TODO: if ignore_prior, one should use *like* covariance (this is *post*)
covmat = self._load_covmat(self.output)[0]
# scale by conditional parameter widths (since not using correlation structure)
scales = np.minimum(1 / np.sqrt(np.diag(np.linalg.inv(covmat))),
(self._bounds[:, 1] - self._bounds[:, 0]) / 3)
# Cov and affine transformation
# Transform to space where initial point is at centre, and cov is normalised
# Cannot do rotation, as supported minimization routines assume bounds aligned
# with the parameter axes.
self._affine_transform_matrix = np.diag(1 / scales)
self._inv_affine_transform_matrix = np.diag(scales)
self._scales = scales
self._affine_transform_baseline = initial_point
initial_point = self.affine_transform(initial_point)
np.testing.assert_allclose(initial_point,
np.zeros(initial_point.shape))
bounds = np.array(
[self.affine_transform(self._bounds[:, i]) for i in range(2)]).T
# Configure method
if self.method.lower() == "bobyqa":
self.minimizer = pybobyqa.solve
self.kwargs = {
"objfun": (lambda x: -self.logp_transf(x)),
"x0":
initial_point,
"bounds":
np.array(list(zip(*bounds))),
"seek_global_minimum":
(True if get_mpi_size() in [0, 1] else False),
"maxfun":
int(self.max_evals)
}
self.kwargs = recursive_update(deepcopy(self.kwargs),
self.override_bobyqa or {})
self.log.debug(
"Arguments for pybobyqa.solve:\n%r",
{k: v
for k, v in self.kwargs.items() if k != "objfun"})
elif self.method.lower() == "scipy":
self.minimizer = scpminimize
self.kwargs = {
"fun": (lambda x: -self.logp_transf(x)),
"x0": initial_point,
"bounds": bounds,
"options": {
"maxiter": self.max_evals,
"disp": (self.log.getEffectiveLevel() == logging.DEBUG)
}
}
self.kwargs = recursive_update(deepcopy(self.kwargs),
self.override_scipy or {})
self.log.debug(
"Arguments for scipy.optimize.minimize:\n%r",
{k: v
for k, v in self.kwargs.items() if k != "fun"})
else:
methods = ["bobyqa", "scipy"]
raise LoggedError(self.log,
"Method '%s' not recognized. Try one of %r.",
self.method, methods)
def initialize(self):
"""Initializes the sampler:
creates the proposal distribution and draws the initial sample."""
self.log.debug("Initializing")
for p in [
"burn_in", "max_tries", "output_every", "check_every",
"callback_every"
]:
setattr(
self, p,
read_dnumber(getattr(self, p), self.model.prior.d(),
dtype=int))
if self.callback_every is None:
self.callback_every = self.check_every
# Burning-in countdown -- the +1 accounts for the initial point (always accepted)
self.burn_in_left = self.burn_in + 1
# Max # checkpoints to wait, in case one process dies without sending MPI_ABORT
self.been_waiting = 0
self.max_waiting = max(50, self.max_tries / self.model.prior.d())
if self.resuming and (max(self.mpi_size or 0, 1) != max(
get_mpi_size(), 1)):
self.log.error(
"Cannot resume a sample with a different number of chains: "
"was %d and now is %d.", max(self.mpi_size, 1),
max(get_mpi_size(), 1))
raise HandledException
if not self.resuming and self.output:
# Delete previous files (if not "forced", the run would have already failed)
if ((os.path.abspath(self.covmat_filename()) != os.path.abspath(
str(self.covmat)))):
try:
os.remove(self.covmat_filename())
except OSError:
pass
# There may be more that chains than expected,
# if #ranks was bigger in a previous run
i = 0
while True:
i += 1
collection_filename, _ = self.output.prepare_collection(str(i))
try:
os.remove(collection_filename)
except OSError:
break
# One collection per MPI process: `name` is the MPI rank + 1
name = str(1 + (lambda r: r if r is not None else 0)(get_mpi_rank()))
self.collection = Collection(self.model,
self.output,
name=name,
resuming=self.resuming)
self.current_point = OnePoint(self.model, OutputDummy({}), name=name)
# Use standard MH steps by default
self.get_new_sample = self.get_new_sample_metropolis
# Prepare oversampling / dragging if applicable
self.effective_max_samples = self.max_samples
if self.oversample and self.drag:
self.log.error("Choose either oversampling or dragging, not both.")
raise HandledException
if self.oversample:
factors, blocks = self.model.likelihood._speeds_of_params(
int_speeds=True)
self.oversampling_factors = factors
self.log.info("Oversampling with factors:\n" + "\n".join([
" %d : %r" % (f, b)
for f, b in zip(self.oversampling_factors, blocks)
]))
self.i_last_slow_block = None
# No way right now to separate slow and fast
slow_params = list(self.model.parameterization.sampled_params())
elif self.drag:
speeds, blocks = self.model.likelihood._speeds_of_params(
fast_slow=True, int_speeds=True)
# For now, no blocking inside either fast or slow: just 2 blocks
self.i_last_slow_block = 0
if np.all(speeds == speeds[0]):
self.log.error(
"All speeds are equal or too similar: cannot drag! "
"Make sure to define accurate likelihoods' speeds.")
raise HandledException
# Make the 1st factor 1:
speeds = [1, speeds[1] / speeds[0]]
# Target: dragging step taking as long as slow step
self.drag_interp_steps = self.drag * speeds[1]
# Per dragging step, the (fast) posterior is evaluated *twice*,
self.drag_interp_steps /= 2
self.drag_interp_steps = int(np.round(self.drag_interp_steps))
fast_params = list(chain(*blocks[1 + self.i_last_slow_block:]))
# Not too much or too little dragging
drag_limits = [(int(l) * len(fast_params) if l is not None else l)
for l in self.drag_limits]
if drag_limits[
0] is not None and self.drag_interp_steps < drag_limits[0]:
self.log.warning(
"Number of dragging steps clipped from below: was not "
"enough to efficiently explore the fast directions -- "
"avoid this limit by decreasing 'drag_limits[0]'.")
self.drag_interp_steps = drag_limits[0]
if drag_limits[
1] is not None and self.drag_interp_steps > drag_limits[1]:
self.log.warning(
"Number of dragging steps clipped from above: "
"excessive, probably inefficient, exploration of the "
"fast directions -- "
"avoid this limit by increasing 'drag_limits[1]'.")
self.drag_interp_steps = drag_limits[1]
# Re-scale steps between checkpoint and callback to the slow dimensions only
slow_params = list(chain(*blocks[:1 + self.i_last_slow_block]))
self.n_slow = len(slow_params)
for p in ["check_every", "callback_every"]:
setattr(
self, p,
int(getattr(self, p) * self.n_slow / self.model.prior.d()))
self.log.info("Dragging with oversampling per step:\n" +
"\n".join([
" %d : %r" % (f, b)
for f, b in zip([1, self.drag_interp_steps],
[blocks[0], fast_params])
]))
self.get_new_sample = self.get_new_sample_dragging
else:
_, blocks = self.model.likelihood._speeds_of_params()
self.oversampling_factors = [1 for b in blocks]
slow_params = list(self.model.parameterization.sampled_params())
self.n_slow = len(slow_params)
# Turn parameter names into indices
self.blocks = [[
list(self.model.parameterization.sampled_params()).index(p)
for p in b
] for b in blocks]
self.proposer = BlockedProposer(
self.blocks,
oversampling_factors=self.oversampling_factors,
i_last_slow_block=self.i_last_slow_block,
proposal_scale=self.proposal_scale)
# Build the initial covariance matrix of the proposal, or load from checkpoint
if self.resuming:
covmat = np.loadtxt(self.covmat_filename())
self.log.info("Covariance matrix from checkpoint.")
else:
covmat = self.initial_proposal_covmat(slow_params=slow_params)
self.log.info("Initial covariance matrix.")
self.log.debug(
"Sampling with covmat:\n%s",
DataFrame(
covmat,
columns=self.model.parameterization.sampled_params(),
index=self.model.parameterization.sampled_params()).to_string(
line_width=_line_width))
self.proposer.set_covariance(covmat)
# Prepare callback function
if self.callback_function is not None:
self.callback_function_callable = (get_external_function(
self.callback_function))
def initialize(self):
"""Initializes the sampler:
creates the proposal distribution and draws the initial sample."""
if not self.model.prior.d():
raise LoggedError(self.log,
"No parameters being varied for sampler")
self.log.debug("Initializing")
# MARKED FOR DEPRECATION IN v3.0
if getattr(self, "oversample", None) is not None:
self.log.warning(
"*DEPRECATION*: `oversample` will be deprecated in the "
"next version. Oversampling is now requested by setting "
"`oversample_power` > 0.")
# END OF DEPRECATION BLOCK
# MARKED FOR DEPRECATION IN v3.0
if getattr(self, "check_every", None) is not None:
self.log.warning(
"*DEPRECATION*: `check_every` will be deprecated in the "
"next version. Please use `learn_every` instead.")
# BEHAVIOUR TO BE REPLACED BY ERROR:
self.learn_every = getattr(self, "check_every")
# END OF DEPRECATION BLOCK
if self.callback_every is None:
self.callback_every = self.learn_every
self._quants_d_units = []
for q in ["max_tries", "learn_every", "callback_every", "burn_in"]:
number = NumberWithUnits(getattr(self, q), "d", dtype=int)
self._quants_d_units.append(number)
setattr(self, q, number)
self.output_every = NumberWithUnits(self.output_every, "s", dtype=int)
if is_main_process():
if self.output.is_resuming() and (max(self.mpi_size or 0, 1) !=
max(get_mpi_size(), 1)):
raise LoggedError(
self.log,
"Cannot resume a run with a different number of chains: "
"was %d and now is %d.", max(self.mpi_size, 1),
max(get_mpi_size(), 1))
if more_than_one_process():
if get_mpi().Get_version()[0] < 3:
raise LoggedError(
self.log, "MPI use requires MPI version 3.0 or "
"higher to support IALLGATHER.")
sync_processes()
# One collection per MPI process: `name` is the MPI rank + 1
name = str(1 + (lambda r: r if r is not None else 0)(get_mpi_rank()))
self.collection = Collection(self.model,
self.output,
name=name,
resuming=self.output.is_resuming())
self.current_point = OneSamplePoint(self.model)
# Use standard MH steps by default
self.get_new_sample = self.get_new_sample_metropolis
# Prepare callback function
if self.callback_function is not None:
self.callback_function_callable = (get_external_function(
self.callback_function))
# Useful for getting last points added inside callback function
self.last_point_callback = 0
# Monitoring/restore progress
if is_main_process():
cols = [
"N", "timestamp", "acceptance_rate", "Rminus1", "Rminus1_cl"
]
self.progress = DataFrame(columns=cols)
self.i_learn = 1
if self.output and not self.output.is_resuming():
with open(self.progress_filename(), "w",
encoding="utf-8") as progress_file:
progress_file.write("# " +
" ".join(self.progress.columns) + "\n")
# Get first point, to be discarded -- not possible to determine its weight
# Still, we need to compute derived parameters, since, as the proposal "blocked",
# we may be saving the initial state of some block.
# NB: if resuming but nothing was written (burn-in not finished): re-start
if self.output.is_resuming() and len(self.collection):
initial_point = (self.collection[
self.collection.sampled_params].iloc[len(self.collection) -
1]).values.copy()
logpost = -(self.collection[_minuslogpost].iloc[
len(self.collection) - 1].copy())
logpriors = -(self.collection[self.collection.minuslogprior_names].
iloc[len(self.collection) - 1].copy())
loglikes = -0.5 * (self.collection[self.collection.chi2_names].
iloc[len(self.collection) - 1].copy())
derived = (self.collection[self.collection.derived_params].iloc[
len(self.collection) - 1].values.copy())
else:
# NB: max_tries adjusted to dim instead of #cycles (blocking not computed yet)
self.max_tries.set_scale(self.model.prior.d())
self.log.info(
"Getting initial point... (this may take a few seconds)")
initial_point, logpost, logpriors, loglikes, derived = \
self.model.get_valid_point(max_tries=self.max_tries.value)
# If resuming but no existing chain, assume failed run and ignore blocking
# if speeds measurement requested
if self.output.is_resuming() and not len(self.collection) \
and self.measure_speeds:
self.blocking = None
if self.measure_speeds and self.blocking:
self.log.warning(
"Parameter blocking manually fixed: speeds will not be measured."
)
elif self.measure_speeds:
n = None if self.measure_speeds is True else int(
self.measure_speeds)
self.model.measure_and_set_speeds(n=n, discard=0)
self.set_proposer_blocking()
self.set_proposer_covmat(load=True)
self.current_point.add(initial_point,
derived=derived,
logpost=logpost,
logpriors=logpriors,
loglikes=loglikes)
self.log.info("Initial point: %s", self.current_point)
# Max #(learn+convergence checks) to wait,
# in case one process dies without sending MPI_ABORT
self.been_waiting = 0
self.max_waiting = max(50, self.max_tries.unit_value)
# Burning-in countdown -- the +1 accounts for the initial point (always accepted)
self.burn_in_left = self.burn_in.value * self.current_point.output_thin + 1
# Initial dummy checkpoint
# (needed when 1st "learn point" not reached in prev. run)
self.write_checkpoint()
def initialize(self):
"""Imports the PolyChord sampler and prepares its arguments."""
if am_single_or_primary_process(
): # rank = 0 (MPI master) or None (no MPI)
self.log.info("Initializing")
# If path not given, try using general path to modules
if not self.path and self.path_install:
self.path = get_path(self.path_install)
if self.path:
if am_single_or_primary_process():
self.log.info("Importing *local* PolyChord from " + self.path)
if not os.path.exists(os.path.realpath(self.path)):
raise LoggedError(
self.log, "The given path does not exist. "
"Try installing PolyChord with "
"'cobaya-install polychord -m [modules_path]")
pc_build_path = get_build_path(self.path)
if not pc_build_path:
raise LoggedError(
self.log, "Either PolyChord is not in the given folder, "
"'%s', or you have not compiled it.", self.path)
# Inserting the previously found path into the list of import folders
sys.path.insert(0, pc_build_path)
else:
self.log.info("Importing *global* PolyChord.")
try:
import pypolychord
from pypolychord.settings import PolyChordSettings
self.pc = pypolychord
except ImportError:
raise LoggedError(
self.log, "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'")
# Prepare arguments and settings
self.nDims = self.model.prior.d()
self.nDerived = (len(self.model.parameterization.derived_params()) +
len(self.model.prior) +
len(self.model.likelihood._likelihoods))
if self.logzero is None:
self.logzero = np.nan_to_num(-np.inf)
if self.max_ndead == np.inf:
self.max_ndead = -1
for p in ["nlive", "nprior", "max_ndead"]:
setattr(self, p,
read_dnumber(getattr(self, p), self.nDims, dtype=int))
# 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.feedback = values[self.log.getEffectiveLevel()]
try:
output_folder = getattr(self.output, "folder")
output_prefix = getattr(self.output, "prefix") or ""
self.read_resume = self.resuming
except AttributeError:
# dummy output -- no resume!
self.read_resume = False
from tempfile import gettempdir
output_folder = gettempdir()
if am_single_or_primary_process():
from random import random
output_prefix = hex(int(random() * 16**6))[2:]
else:
output_prefix = None
if more_than_one_process():
output_prefix = get_mpi_comm().bcast(output_prefix, root=0)
self.base_dir = os.path.join(output_folder, self.base_dir)
self.file_root = output_prefix
if am_single_or_primary_process():
# Creating output folder, if it does not exist (just one process)
if not os.path.exists(self.base_dir):
os.makedirs(self.base_dir)
# Idem, a clusters folder if needed -- notice that PolyChord's default
# is "True", here "None", hence the funny condition below
if self.do_clustering is not False: # None here means "default"
try:
os.makedirs(os.path.join(self.base_dir, clusters))
except OSError: # exists!
pass
self.log.info("Storing raw PolyChord output in '%s'.",
self.base_dir)
# Exploiting the speed hierarchy
if self.blocking:
speeds, blocks = self.model.likelihood._check_speeds_of_params(
self.blocking)
else:
speeds, blocks = self.model.likelihood._speeds_of_params(
int_speeds=True)
blocks_flat = list(chain(*blocks))
self.ordering = [
blocks_flat.index(p)
for p in self.model.parameterization.sampled_params()
]
self.grade_dims = np.array([len(block) for block in blocks])
# bugfix: pypolychord's C interface for Fortran does not like int numpy types
self.grade_dims = [int(x) for x in self.grade_dims]
# Steps per block
# NB: num_repeats is ignored by PolyChord when int "grade_frac" given,
# so needs to be applied by hand.
# Make sure that speeds are integer, and that the slowest is 1,
# for a straightforward application of num_repeats
speeds = relative_to_int(speeds, 1)
# In num_repeats, `d` is interpreted as dimension of each block
self.grade_frac = [
int(speed * read_dnumber(self.num_repeats, dim_block))
for speed, dim_block in zip(speeds, self.grade_dims)
]
# Assign settings
pc_args = [
"nlive", "num_repeats", "nprior", "do_clustering",
"precision_criterion", "max_ndead", "boost_posterior", "feedback",
"logzero", "posteriors", "equals", "compression_factor",
"cluster_posteriors", "write_resume", "read_resume", "write_stats",
"write_live", "write_dead", "base_dir", "grade_frac", "grade_dims",
"feedback", "read_resume", "base_dir", "file_root", "grade_frac",
"grade_dims"
]
# As stated above, num_repeats is ignored, so let's not pass it
pc_args.pop(pc_args.index("num_repeats"))
self.pc_settings = PolyChordSettings(
self.nDims,
self.nDerived,
seed=(self.seed if self.seed is not None else -1),
**{
p: getattr(self, p)
for p in pc_args if getattr(self, p) is not None
})
# prior conversion from the hypercube
bounds = self.model.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.model.parameterization.sampled_params()
params = [params_names[i] for i in sorted(list(set(inf[0])))]
raise LoggedError(
self.log,
"PolyChord needs bounded priors, but the parameter(s) '"
"', '".join(params) + "' is(are) unbounded.")
locs = bounds[:, 0]
scales = bounds[:, 1] - bounds[:, 0]
# This function re-scales the parameters AND puts them in the right order
self.pc_prior = lambda x: (locs + np.array(x)[self.ordering] * scales
).tolist()
# We will need the volume of the prior domain, since PolyChord divides by it
self.logvolume = np.log(np.prod(scales))
# Prepare callback function
if self.callback_function is not None:
self.callback_function_callable = (get_external_function(
self.callback_function))
self.last_point_callback = 0
# Prepare runtime live and dead points collections
self.live = Collection(self.model,
None,
name="live",
initial_size=self.pc_settings.nlive)
self.dead = Collection(self.model, self.output, name="dead")
self.n_sampled = len(self.model.parameterization.sampled_params())
self.n_derived = len(self.model.parameterization.derived_params())
self.n_priors = len(self.model.prior)
self.n_likes = len(self.model.likelihood._likelihoods)
# Done!
if am_single_or_primary_process():
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 initialise(self):
"""Initialises the sampler:
creates the proposal distribution and draws the initial sample."""
self.log.info("Initializing")
# Burning-in countdown -- the +1 accounts for the initial point (always accepted)
self.burn_in_left = self.burn_in + 1
# One collection per MPI process: `name` is the MPI rank + 1
name = str(1 + (lambda r: r if r is not None else 0)(get_mpi_rank()))
self.collection = Collection(self.parametrization,
self.likelihood,
self.output,
name=name)
self.current_point = OnePoint(self.parametrization,
self.likelihood,
self.output,
name=name)
# Use the standard steps by default
self.get_new_sample = self.get_new_sample_metropolis
# Prepare oversampling / fast-dragging if applicable
self.effective_max_samples = self.max_samples
if self.oversample and self.drag:
self.log.error(
"Choose either oversampling or fast-dragging, not both.")
raise HandledException
# if (self.oversample or self.drag) and len(set(factors)) == 1:
# self.log.error("All block speeds are similar: "
# "no dragging or oversampling possible.")
# raise HandledException
if self.oversample:
factors, blocks = self.likelihood.speeds_of_params(
oversampling_factors=True)
self.oversampling_factors = factors
# WIP: actually, we would have to re-normalise to the dimension of the blocks.
self.log.info("Oversampling with factors:\n" + "\n".join([
" %d : %r" % (f, b)
for f, b in zip(self.oversampling_factors, blocks)
]))
# WIP: useless until likelihoods have STATES!
self.log.error("Sorry, oversampling is WIP")
raise HandledException
elif self.drag:
# WIP: for now, can only separate between theory and likelihoods
# until likelihoods have states
if not self.likelihood.theory:
self.log.error(
"WIP: dragging disabled for now when no theory code present."
)
raise HandledException
# if self.max_speed_slow < min(speeds) or self.max_speed_slow >= max(speeds):
# self.log.error("The maximum speed considered slow, `max_speed_slow`, must be "
# "%g <= `max_speed_slow < %g, and is %g",
# min(speeds), max(speeds), self.max_speed_slow)
# raise HandledException
speeds, blocks = self.likelihood.speeds_of_params(int_speeds=True,
fast_slow=True)
if np.all(speeds == speeds[0]):
self.log.error(
"All speeds are equal: cannot drag! Make sure to define, "
"especially, the speed of the fastest likelihoods.")
self.i_last_slow_block = 0 # just theory can be slow for now
fast_params = list(chain(*blocks[1 + self.i_last_slow_block:]))
self.n_slow = sum(
len(blocks[i]) for i in range(1 + self.i_last_slow_block))
self.drag_interp_steps = int(self.drag *
np.round(min(speeds[1:]) / speeds[0]))
self.log.info("Dragging with oversampling per step:\n" +
"\n".join([
" %d : %r" % (f, b)
for f, b in zip([1, self.drag_interp_steps],
[blocks[0], fast_params])
]))
self.get_new_sample = self.get_new_sample_dragging
else:
_, blocks = self.likelihood.speeds_of_params()
self.oversampling_factors = [1 for b in blocks]
self.n_slow = len(self.parametrization.sampled_params())
# Turn parameter names into indices
blocks = [[
list(self.parametrization.sampled_params().keys()).index(p)
for p in b
] for b in blocks]
self.proposer = BlockedProposer(
blocks,
oversampling_factors=getattr(self, "oversampling_factors", None),
i_last_slow_block=getattr(self, "i_last_slow_block", None),
propose_scale=self.propose_scale)
# Build the initial covariance matrix of the proposal
covmat = self.initial_proposal_covmat()
self.log.info("Sampling with covariance matrix:")
self.log.info("%r", covmat)
self.proposer.set_covariance(covmat)
# Prepare callback function
if self.callback_function is not None:
self.callback_function_callable = (get_external_function(
self.callback_function))
def post(info, sample=None):
logger_setup(info.get(_debug), info.get(_debug_file))
log = logging.getLogger(__name__.split(".")[-1])
try:
info_post = info[_post]
except KeyError:
log.error("No 'post' block given. Nothing to do!")
raise HandledException
if get_mpi_rank():
log.warning(
"Post-processing is not yet MPI-able. Doing nothing for rank > 1 processes."
)
return
# 1. Load existing sample
output_in = Output(output_prefix=info.get(_output_prefix), resume=True)
info_in = load_input(output_in.file_full) if output_in else deepcopy(info)
dummy_model_in = DummyModel(info_in[_params], info_in[_likelihood],
info_in.get(_prior, None),
info_in.get(_theory, None))
if output_in:
i = 0
while True:
try:
collection = Collection(dummy_model_in,
output_in,
name="%d" % (1 + i),
load=True,
onload_skip=info_post.get("skip", 0),
onload_thin=info_post.get("thin", 1))
if i == 0:
collection_in = collection
else:
collection_in._append(collection)
i += 1
except IOError:
break
elif sample:
if isinstance(sample, Collection):
sample = [sample]
collection_in = deepcopy(sample[0])
for s in sample[1:]:
try:
collection_in._append(s)
except:
log.error("Failed to load some of the input samples.")
raise HandledException
i = len(sample)
else:
log.error(
"Not output from where to load from or input collections given.")
raise HandledException
log.info("Loaded %d chain%s. Will process %d samples.", i,
"s" if i - 1 else "", collection_in.n())
if collection_in.n() <= 1:
log.error(
"Not enough samples for post-processing. Try using a larger sample, "
"or skipping or thinning less.")
raise HandledException
# 2. Compare old and new info: determine what to do
add = info_post.get("add", {})
remove = info_post.get("remove", {})
# Add a dummy 'one' likelihood, to absorb unused parameters
if not add.get(_likelihood):
add[_likelihood] = odict()
add[_likelihood].update({"one": None})
# Expand the "add" info
add = get_full_info(add)
# 2.1 Adding/removing derived parameters and changes in priors of sampled parameters
out = {_params: deepcopy(info_in[_params])}
for p in remove.get(_params, {}):
pinfo = info_in[_params].get(p)
if pinfo is None or not is_derived_param(pinfo):
log.error(
"You tried to remove parameter '%s', which is not a derived paramter. "
"Only derived parameters can be removed during post-processing.",
p)
raise HandledException
out[_params].pop(p)
mlprior_names_add = []
for p, pinfo in add.get(_params, {}).items():
pinfo_in = info_in[_params].get(p)
if is_sampled_param(pinfo):
if not is_sampled_param(pinfo_in):
# No added sampled parameters (de-marginalisation not implemented)
if pinfo_in is None:
log.error(
"You added a new sampled parameter %r (maybe accidentaly "
"by adding a new likelihood that depends on it). "
"Adding new sampled parameters is not possible. Try fixing "
"it to some value.", p)
raise HandledException
else:
log.error(
"You tried to change the prior of parameter '%s', "
"but it was not a sampled parameter. "
"To change that prior, you need to define as an external one.",
p)
raise HandledException
if mlprior_names_add[:1] != _prior_1d_name:
mlprior_names_add = (
[_minuslogprior + _separator + _prior_1d_name] +
mlprior_names_add)
elif is_derived_param(pinfo):
if p in out[_params]:
log.error(
"You tried to add derived parameter '%s', which is already "
"present. To force its recomputation, 'remove' it too.", p)
raise HandledException
elif is_fixed_param(pinfo):
# Only one possibility left "fixed" parameter that was not present before:
# input of new likelihood, or just an argument for dynamical derived (dropped)
if ((p in info_in[_params] and pinfo[_p_value] !=
(pinfo_in or {}).get(_p_value, None))):
log.error(
"You tried to add a fixed parameter '%s: %r' that was already present"
" but had a different value or was not fixed. This is not allowed. "
"The old info of the parameter was '%s: %r'", p,
dict(pinfo), p, dict(pinfo_in))
raise HandledException
else:
log.error("This should not happen. Contact the developers.")
raise HandledException
out[_params][p] = pinfo
# For the likelihood only, turn the rest of *derived* parameters into constants,
# so that the likelihoods do not try to compute them)
# But be careful to exclude *input* params that have a "derived: True" value
# (which in "full info" turns into "derived: 'lambda [x]: [x]'")
out_params_like = deepcopy(out[_params])
for p, pinfo in out_params_like.items():
if ((is_derived_param(pinfo) and not (_p_value in pinfo)
and p not in add.get(_params, {}))):
out_params_like[p] = {_p_value: np.nan, _p_drop: True}
parameterization_like = Parameterization(out_params_like,
ignore_unused_sampled=True)
# 2.2 Manage adding/removing priors and likelihoods
warn_remove = False
for level in [_prior, _likelihood]:
out[level] = getattr(dummy_model_in, level)
if level == _prior:
out[level].remove(_prior_1d_name)
for pdf in info_post.get("remove", {}).get(level, []) or []:
try:
out[level].remove(pdf)
warn_remove = True
except ValueError:
log.error(
"Trying to remove %s '%s', but it is not present. "
"Existing ones: %r", level, pdf, out[level])
raise HandledException
if warn_remove:
log.warning("You are removing a prior or likelihood pdf. "
"Notice that if the resulting posterior is much wider "
"than the original one, or displaced enough, "
"it is probably safer to explore it directly.")
if _prior in add:
mlprior_names_add += [
_minuslogprior + _separator + name for name in add[_prior]
]
out[_prior] += list(add[_prior])
prior_recompute_1d = (mlprior_names_add[:1] == [
_minuslogprior + _separator + _prior_1d_name
])
# Don't initialise the theory code if not adding/recomputing theory,
# theory-derived params or likelihoods
recompute_theory = info_in.get(_theory) and not (list(
add[_likelihood]) == ["one"] and not any([
is_derived_param(pinfo) for pinfo in add.get(_params, {}).values()
]))
if recompute_theory:
# Inherit from the original chain (needs input|output_params, renames, etc
theory = list(info_in[_theory].keys())[0]
info_theory_out = odict([[
theory,
recursive_update(deepcopy(info_in[_theory][theory]),
add.get(_theory, {theory: {}})[theory])
]])
else:
info_theory_out = None
chi2_names_add = [
_chi2 + _separator + name for name in add[_likelihood]
if name is not "one"
]
out[_likelihood] += [l for l in add[_likelihood] if l is not "one"]
if recompute_theory:
log.warn(
"You are recomputing the theory, but in the current version this does "
"not force recomputation of any likelihood or derived parameter, "
"unless explicitly removed+added.")
for level in [_prior, _likelihood]:
for i, x_i in enumerate(out[level]):
if x_i in list(out[level])[i + 1:]:
log.error(
"You have added %s '%s', which was already present. If you "
"want to force its recomputation, you must also 'remove' it.",
level, x_i)
raise HandledException
# 3. Create output collection
if "suffix" not in info_post:
log.error("You need to provide a 'suffix' for your chains.")
raise HandledException
# Use default prefix if it exists. If it does not, produce no output by default.
# {post: {output: None}} suppresses output, and if it's a string, updates it.
out_prefix = info_post.get(_output_prefix, info.get(_output_prefix))
if out_prefix not in [None, False]:
out_prefix += "_" + _post + "_" + info_post["suffix"]
output_out = Output(output_prefix=out_prefix,
force_output=info.get(_force))
info_out = deepcopy(info)
info_out[_post] = info_post
# Updated with input info and extended (full) add info
info_out.update(info_in)
info_out[_post]["add"] = add
dummy_model_out = DummyModel(out[_params],
out[_likelihood],
info_prior=out[_prior])
if recompute_theory:
theory = list(info_theory_out.keys())[0]
if _input_params not in info_theory_out[theory]:
log.error(
"You appear to be post-processing a chain generated with an older "
"version of Cobaya. For post-processing to work, please edit the "
"'[root]__full.info' file of the original chain to add, inside the "
"theory code block, the list of its input parameters. E.g.\n----\n"
"theory:\n %s:\n input_params: [param1, param2, ...]\n"
"----\nIf you get strange errors later, it is likely that you did not "
"specify the correct set of theory parameters.\n"
"The full set of input parameters are %s.", theory,
list(dummy_model_out.parameterization.input_params()))
raise HandledException
prior_add = Prior(dummy_model_out.parameterization, add.get(_prior))
likelihood_add = Likelihood(add[_likelihood],
parameterization_like,
info_theory=info_theory_out,
modules=info.get(_path_install))
# Remove auxiliary "one" before dumping -- 'add' *is* info_out[_post]["add"]
add[_likelihood].pop("one")
if likelihood_add.theory:
# Make sure that theory.needs is called at least once, for adjustments
likelihood_add.theory.needs()
collection_out = Collection(dummy_model_out, output_out, name="1")
output_out.dump_info({}, info_out)
# 4. Main loop!
log.info("Running post-processing...")
last_percent = 0
for i, point in enumerate(collection_in.data.itertuples()):
log.debug("Point: %r", point)
sampled = [
getattr(point, param)
for param in dummy_model_in.parameterization.sampled_params()
]
derived = odict(
[[param, getattr(point, param, None)]
for param in dummy_model_out.parameterization.derived_params()])
inputs = odict([[
param,
getattr(
point, param,
dummy_model_in.parameterization.constant_params().get(
param,
dummy_model_out.parameterization.constant_params().get(
param, None)))
] for param in dummy_model_out.parameterization.input_params()])
# Solve inputs that depend on a function and were not saved
# (we don't use the Parameterization_to_input method in case there are references
# to functions that cannot be loaded at the moment)
for p, value in inputs.items():
if value is None:
func = dummy_model_out.parameterization._input_funcs[p]
args = dummy_model_out.parameterization._input_args[p]
inputs[p] = func(*[getattr(point, arg) for arg in args])
# Add/remove priors
priors_add = prior_add.logps(sampled)
if not prior_recompute_1d:
priors_add = priors_add[1:]
logpriors_add = odict(zip(mlprior_names_add, priors_add))
logpriors_new = [
logpriors_add.get(name, -getattr(point, name, 0))
for name in collection_out.minuslogprior_names
]
if log.getEffectiveLevel() <= logging.DEBUG:
log.debug("New set of priors: %r",
dict(zip(dummy_model_out.prior, logpriors_new)))
if -np.inf in logpriors_new:
continue
# Add/remove likelihoods
output_like = []
if likelihood_add:
# Notice "one" (last in likelihood_add) is ignored: not in chi2_names
loglikes_add = odict(
zip(chi2_names_add,
likelihood_add.logps(inputs, _derived=output_like)))
output_like = dict(zip(likelihood_add.output_params, output_like))
else:
loglikes_add = dict()
loglikes_new = [
loglikes_add.get(name, -0.5 * getattr(point, name, 0))
for name in collection_out.chi2_names
]
if log.getEffectiveLevel() <= logging.DEBUG:
log.debug("New set of likelihoods: %r",
dict(zip(dummy_model_out.likelihood, loglikes_new)))
if output_like:
log.debug("New set of likelihood-derived parameters: %r",
output_like)
if -np.inf in loglikes_new:
continue
# Add/remove derived parameters and change priors of sampled parameters
for p in add[_params]:
if p in dummy_model_out.parameterization._directly_output:
derived[p] = output_like[p]
elif p in dummy_model_out.parameterization._derived_funcs:
func = dummy_model_out.parameterization._derived_funcs[p]
args = dummy_model_out.parameterization._derived_args[p]
derived[p] = func(*[
getattr(point, arg, output_like.get(arg, None))
for arg in args
])
if log.getEffectiveLevel() <= logging.DEBUG:
log.debug(
"New derived parameters: %r",
dict([[
p, derived[p]
] for p in dummy_model_out.parameterization.derived_params()
if p in add[_params]]))
# Save to the collection (keep old weight for now)
collection_out.add(sampled,
derived=derived.values(),
weight=getattr(point, _weight),
logpriors=logpriors_new,
loglikes=loglikes_new)
# Display progress
percent = np.round(i / collection_in.n() * 100)
if percent != last_percent and not percent % 5:
last_percent = percent
progress_bar(log, percent, " (%d/%d)" % (i, collection_in.n()))
if not collection_out.data.last_valid_index():
log.error(
"No elements in the final sample. Possible causes: "
"added a prior or likelihood valued zero over the full sampled domain, "
"or the computation of the theory failed everywhere, etc.")
raise HandledException
# Reweight -- account for large dynamic range!
# Prefer to rescale +inf to finite, and ignore final points with -inf.
# Remove -inf's (0-weight), and correct indices
difflogmax = max(collection_in[_minuslogpost] -
collection_out[_minuslogpost])
collection_out.data[_weight] *= np.exp(collection_in[_minuslogpost] -
collection_out[_minuslogpost] -
difflogmax)
collection_out.data = (
collection_out.data[collection_out.data.weight > 0].reset_index(
drop=True))
collection_out._n = collection_out.data.last_valid_index() + 1
# Write!
collection_out._out_update()
log.info("Finished! Final number of samples: %d", collection_out.n())
return info_out, {"sample": collection_out}
