"""Container for the results of running autodiff variational inference"""
from collections import OrderedDict
from typing import Dict, Optional, Tuple, Union
import numpy as np
import pandas as pd
from cmdstanpy.cmdstan_args import Method
from cmdstanpy.utils import BaseType, scan_variational_csv
from .metadata import InferenceMetadata
from .runset import RunSet
[docs]class CmdStanVB:
"""
Container for outputs from CmdStan variational run.
Created by :meth:`CmdStanModel.variational`.
"""
def __init__(self, runset: RunSet) -> None:
"""Initialize object."""
if not runset.method == Method.VARIATIONAL:
raise ValueError(
'Wrong runset method, expecting variational inference, '
'found method {}'.format(runset.method)
)
self.runset = runset
self._set_variational_attrs(runset.csv_files[0])
def __repr__(self) -> str:
repr = 'CmdStanVB: model={}{}'.format(
self.runset.model, self.runset._args.method_args.compose(0, cmd=[])
)
repr = '{}\n csv_file:\n\t{}\n output_file:\n\t{}'.format(
repr,
'\n\t'.join(self.runset.csv_files),
'\n\t'.join(self.runset.stdout_files),
)
# TODO - diagnostic, profiling files
return repr
def __getattr__(self, attr: str) -> Union[np.ndarray, float]:
"""Synonymous with ``fit.stan_variable(attr)"""
try:
return self.stan_variable(attr)
except ValueError as e:
# pylint: disable=raise-missing-from
raise AttributeError(*e.args)
def _set_variational_attrs(self, sample_csv_0: str) -> None:
meta = scan_variational_csv(sample_csv_0)
self._metadata = InferenceMetadata(meta)
# these three assignments don't grant type information
self._column_names: Tuple[str, ...] = meta['column_names']
self._eta: float = meta['eta']
self._variational_mean: np.ndarray = meta['variational_mean']
self._variational_sample: np.ndarray = meta['variational_sample']
@property
def columns(self) -> int:
"""
Total number of information items returned by sampler.
Includes approximation information and names of model parameters
and computed quantities.
"""
return len(self._column_names)
@property
def column_names(self) -> Tuple[str, ...]:
"""
Names of information items returned by sampler for each draw.
Includes approximation information and names of model parameters
and computed quantities.
"""
return self._column_names
@property
def eta(self) -> float:
"""
Step size scaling parameter 'eta'
"""
return self._eta
@property
def variational_params_np(self) -> np.ndarray:
"""
Returns inferred parameter means as numpy array.
"""
return self._variational_mean
@property
def variational_params_pd(self) -> pd.DataFrame:
"""
Returns inferred parameter means as pandas DataFrame.
"""
return pd.DataFrame([self._variational_mean], columns=self.column_names)
@property
def variational_params_dict(self) -> Dict[str, np.ndarray]:
"""Returns inferred parameter means as Dict."""
return OrderedDict(zip(self.column_names, self._variational_mean))
@property
def metadata(self) -> InferenceMetadata:
"""
Returns object which contains CmdStan configuration as well as
information about the names and structure of the inference method
and model output variables.
"""
return self._metadata
[docs] def stan_variable(self, var: str) -> Union[np.ndarray, float]:
"""
Return a numpy.ndarray which contains the estimates for the
for the named Stan program variable where the dimensions of the
numpy.ndarray match the shape of the Stan program variable.
This functionaltiy is also available via a shortcut using ``.`` -
writing ``fit.a`` is a synonym for ``fit.stan_variable("a")``
:param var: variable name
See Also
--------
CmdStanVB.stan_variables
CmdStanMCMC.stan_variable
CmdStanMLE.stan_variable
CmdStanGQ.stan_variable
"""
if var is None:
raise ValueError('No variable name specified.')
if var not in self._metadata.stan_vars_dims:
raise ValueError(
f'Unknown variable name: {var}\n'
'Available variables are '
+ ", ".join(self._metadata.stan_vars_dims)
)
col_idxs = list(self._metadata.stan_vars_cols[var])
shape: Tuple[int, ...] = ()
if len(col_idxs) > 1:
shape = self._metadata.stan_vars_dims[var]
result: np.ndarray = np.asarray(self._variational_mean)[
col_idxs
].reshape(shape, order="F")
if self._metadata.stan_vars_types[var] == BaseType.COMPLEX:
result = result[..., 0] + 1j * result[..., 1]
return result
else:
return float(self._variational_mean[col_idxs[0]])
[docs] def stan_variables(self) -> Dict[str, Union[np.ndarray, float]]:
"""
Return a dictionary mapping Stan program variables names
to the corresponding numpy.ndarray containing the inferred values.
See Also
--------
CmdStanVB.stan_variable
CmdStanMCMC.stan_variables
CmdStanMLE.stan_variables
CmdStanGQ.stan_variables
"""
result = {}
for name in self._metadata.stan_vars_dims.keys():
result[name] = self.stan_variable(name)
return result
@property
def variational_sample(self) -> np.ndarray:
"""Returns the set of approximate posterior output draws."""
return self._variational_sample
[docs] def save_csvfiles(self, dir: Optional[str] = None) -> None:
"""
Move output CSV files to specified directory. If files were
written to the temporary session directory, clean filename.
E.g., save 'bernoulli-201912081451-1-5nm6as7u.csv' as
'bernoulli-201912081451-1.csv'.
:param dir: directory path
See Also
--------
stanfit.RunSet.save_csvfiles
cmdstanpy.from_csv
"""
self.runset.save_csvfiles(dir)