def set_priors(self, priors=None, fixed=None, random=None):
'''
Set priors for one or more existing terms.
Args:
priors (dict): Dict of priors to update. Keys are names of terms
to update; values are the new priors (either a Prior instance,
or an int or float that scales the default priors). Note that
a tuple can be passed as the key, in which case the same prior
will be applied to all terms named in the tuple.
fixed (Prior, int, float, str): a prior specification to apply to
all fixed terms currently included in the model.
random (Prior, int, float, str): a prior specification to apply to
all random terms currently included in the model.
'''
targets = {}
if fixed is not None:
targets.update({name: fixed for name in self.fixed_terms.keys()})
if random is not None:
targets.update({name: random for name in self.random_terms.keys()})
if priors is not None:
for k, prior in priors.items():
for name in listify(k):
if name not in self.terms:
raise ValueError("The model contains no term with "
"the name '%s'." % name)
targets[name] = prior
for name, prior in targets.items():
self.terms[name].prior = prior
def _set_priors(self, priors=None, fixed=None, random=None, match_derived_names=True):
"""Internal version of set_priors(), with same arguments.
Runs during Model.build().
"""
targets = {}
if fixed is not None:
targets.update({name: fixed for name in self.fixed_terms.keys()})
if random is not None:
targets.update({name: random for name in self.random_terms.keys()})
if priors is not None:
for k, prior in priors.items():
for name in listify(k):
term_names = list(self.terms.keys())
msg = "No terms in model match '%s'." % name
if name not in term_names:
terms = self._match_derived_terms(name)
if not match_derived_names or terms is None:
raise ValueError(msg)
for term in terms:
targets[term.name] = prior
else:
targets[name] = prior
for name, prior in targets.items():
self.terms[name].prior = prior
def set_priors(self,
priors=None,
fixed=None,
random=None,
match_derived_names=True):
'''
Set priors for one or more existing terms.
Args:
priors (dict): Dict of priors to update. Keys are names of terms
to update; values are the new priors (either a Prior instance,
or an int or float that scales the default priors). Note that
a tuple can be passed as the key, in which case the same prior
will be applied to all terms named in the tuple.
fixed (Prior, int, float, str): a prior specification to apply to
all fixed terms currently included in the model.
random (Prior, int, float, str): a prior specification to apply to
all random terms currently included in the model.
match_derived_names (bool): if True, the specified prior(s) will be
applied not only to terms that match the keyword exactly,
but to the levels of random effects that were derived from
the original specification with the passed name. For example,
`priors={'condition|subject':0.5}` would apply the prior
to the terms with names '1|subject', 'condition[T.1]|subject',
and so on. If False, an exact match is required for the
prior to be applied.
'''
targets = {}
if fixed is not None:
targets.update({name: fixed for name in self.fixed_terms.keys()})
if random is not None:
targets.update({name: random for name in self.random_terms.keys()})
if priors is not None:
for k, prior in priors.items():
for name in listify(k):
term_names = list(self.terms.keys())
msg = "No terms in model match '%s'." % name
if name not in term_names:
terms = self._match_derived_terms(name)
if not match_derived_names or terms is None:
raise ValueError(msg)
for t in terms:
targets[t.name] = prior
else:
targets[name] = prior
for prior in targets.values():
if isinstance(prior, Prior):
prior._auto_scale = False
for name, prior in targets.items():
self.terms[name].prior = prior
if fixed is not None or random is not None or priors is not None:
self.built = False
def _set_priors(self,
priors=None,
fixed=None,
random=None,
match_derived_names=True):
'''
Internal version of set_priors(), with same arguments.
Runs during Model.build().
'''
targets = {}
if fixed is not None:
targets.update({name: fixed for name in self.fixed_terms.keys()})
if random is not None:
targets.update({name: random for name in self.random_terms.keys()})
if priors is not None:
for k, prior in priors.items():
for name in listify(k):
term_names = list(self.terms.keys())
msg = "No terms in model match '%s'." % name
if name not in term_names:
terms = self._match_derived_terms(name)
if not match_derived_names or terms is None:
raise ValueError(msg)
for t in terms:
targets[t.name] = prior
else:
targets[name] = prior
for name, prior in targets.items():
_type = 'intercept' if name == 'Intercept' else \
'random' if self.terms[name].random else 'fixed'
self.terms[name].prior = self._prepare_prior(prior, _type)
if fixed is not None or random is not None or priors is not None:
self.built = False
def _add(self,
fixed=None,
random=None,
priors=None,
family='gaussian',
link=None,
categorical=None,
append=True):
'''
Internal version of add(), with the same arguments.
Runs during Model.build()
'''
# use cleaned data with NAs removed (if user requested)
data = self.clean_data
# alter this pandas flag to avoid false positive SettingWithCopyWarnings
data.is_copy = False
# Explicitly convert columns to category if desired--though this
# can also be done within the formula using C().
if categorical is not None:
data = data.copy()
cats = listify(categorical)
data[cats] = data[cats].apply(lambda x: x.astype('category'))
if fixed is not None:
if '~' in fixed:
# check to see if formula is using the 'y[event] ~ x' syntax
# (for bernoulli models). If so, chop it into groups:
# 1 = 'y[event]', 2 = 'y', 3 = 'event', 4 = 'x'
# If this syntax is not being used, event = None
event = re.match(r'^((\S+)\[(\S+)\])\s*~(.*)$', fixed)
if event is not None:
fixed = '{}~{}'.format(event.group(2), event.group(4))
y, X = dmatrices(fixed, data=data, NA_action='raise')
y_label = y.design_info.term_names[0]
if event is not None:
# pass in new Y data that has 1 if y=event and 0 otherwise
y_data = y[:,
y.design_info.column_names.index(event.group(1)
)]
y_data = pd.DataFrame({event.group(3): y_data})
self._add_y(y_label, family=family, link=link, data=y_data)
else:
# use Y as-is
self._add_y(y_label, family=family, link=link)
else:
X = dmatrix(fixed, data=data, NA_action='raise')
# Loop over predictor terms
for _name, _slice in X.design_info.term_name_slices.items():
cols = X.design_info.column_names[_slice]
term_data = pd.DataFrame(X[:, _slice], columns=cols)
prior = priors.pop(_name, priors.get('fixed', None))
_type = 'intercept' if _name == 'Intercept' else 'fixed'
prior = self._prepare_prior(prior, _type)
self.terms[_name] = Term(_name, term_data, prior=prior)
# Random effects
if random is not None:
random = listify(random)
for f in random:
f = f.strip()
# Split specification into intercept, predictor, and grouper
patt = r'^([01]+)*[\s\+]*([^\|]+)*\|(.*)'
intcpt, pred, grpr = re.search(patt, f).groups()
label = '{}|{}'.format(pred, grpr) if pred else grpr
prior = priors.pop(label, priors.get('random', None))
prior = self._prepare_prior(prior, 'random')
# Treat all grouping variables as categoricals, regardless of
# their dtype and what the user may have specified in the
# 'categorical' argument.
var_names = re.findall('(\w+)', grpr)
for v in var_names:
if v in data.columns:
data.loc[:, v] = data.loc[:, v].astype('category')
self.clean_data.loc[:, v] = data.loc[:, v]
# Default to including random intercepts
intcpt = 1 if intcpt is None else int(intcpt)
grpr_df = dmatrix('0+%s' % grpr,
data,
return_type='dataframe',
NA_action='raise')
# If there's no predictor, we must be adding random intercepts
if not pred and grpr not in self.terms:
name = '1|' + grpr
pred = np.ones((len(grpr_df), 1))
term = RandomTerm(name,
grpr_df,
pred,
grpr_df.values,
categorical=True,
prior=prior)
self.terms[name] = term
else:
pred_df = dmatrix('%s+%s' % (intcpt, pred),
data,
return_type='dataframe',
NA_action='raise')
# determine value of the 'constant' attribute
const = np.atleast_2d(pred_df.T).T.sum(1).var() == 0
for col, i in pred_df.design_info.column_name_indexes.items(
):
pred_data = pred_df.iloc[:, i]
lev_data = grpr_df.multiply(pred_data, axis=0)
# Also rename intercepts and skip if already added.
# This can happen if user specifies something like
# random=['1|school', 'student|school'].
if col == 'Intercept':
if grpr in self.terms:
continue
label = '1|%s' % grpr
else:
label = col + '|' + grpr
prior = priors.pop(label, priors.get('random', None))
prior = self._prepare_prior(prior, 'random')
# Categorical or continuous is determined from data
ld = lev_data.values
if ((ld == 0) | (ld == 1)).all():
lev_data = lev_data.astype(int)
cat = True
else:
cat = False
pred_data = pred_data[:, None] # Must be 2D later
term = RandomTerm(label,
lev_data,
pred_data,
grpr_df.values,
categorical=cat,
constant=const if const else None,
prior=prior)
self.terms[label] = term
def add(self,
fixed=None,
random=None,
priors=None,
family='gaussian',
link=None,
categorical=None,
append=True):
'''
Adds one or more terms to the model via an R-like formula syntax.
Args:
fixed (str): Optional formula specification of fixed effects.
random (list): Optional list-based specification of random effects.
priors (dict): Optional specification of priors for one or more
terms. A dict where the keys are the names of terms in the
model, and the values are either instances of class Prior or
ints, floats, or strings that specify the width of the priors
on a standardized scale.
family (str, Family): A specification of the model family
(analogous to the family object in R). Either a string, or an
instance of class priors.Family. If a string is passed, a
family with the corresponding name must be defined in the
defaults loaded at Model initialization. Valid pre-defined
families are 'gaussian', 'bernoulli', 'poisson', and 't'.
link (str): The model link function to use. Can be either a string
(must be one of the options defined in the current backend;
typically this will include at least 'identity', 'logit',
'inverse', and 'log'), or a callable that takes a 1D ndarray
or theano tensor as the sole argument and returns one with
the same shape.
categorical (str, list): The names of any variables to treat as
categorical. Can be either a single variable name, or a list
of names. If categorical is None, the data type of the columns
in the DataFrame will be used to infer handling. In cases where
numeric columns are to be treated as categoricals (e.g., random
factors coded as numerical IDs), explicitly passing variable
names via this argument is recommended.
append (bool): if True, terms are appended to the existing model
rather than replacing any existing terms. This allows
formula-based specification of the model in stages.
'''
data = self.data
# Primitive values (floats, strs) can be overwritten with Prior objects
# so we need to make sure to copy first to avoid bad things happening
# if user is re-using same prior dict in multiple models.
if priors is None:
priors = {}
else:
priors = deepcopy(priors)
if not append:
self.reset()
# Explicitly convert columns to category if desired--though this
# can also be done within the formula using C().
if categorical is not None:
data = data.copy()
cats = listify(categorical)
data[cats] = data[cats].apply(lambda x: x.astype('category'))
# Custom patsy.missing.NAAction class. Similar to patsy drop/raise
# defaults, but changes the raised message and logs any dropped rows
NA_handler = Custom_NA(dropna=self.dropna)
# screen fixed terms
if fixed is not None:
if '~' in fixed:
clean_fix = re.sub(r'\[.+\]', '', fixed)
dmatrices(clean_fix, data=data, NA_action=NA_handler)
else:
dmatrix(fixed, data=data, NA_action=NA_handler)
# screen random terms
if random is not None:
for term in listify(random):
for side in term.split('|'):
dmatrix(side, data=data, NA_action=NA_handler)
# update the running list of complete cases
if len(NA_handler.completes):
self.completes.append(NA_handler.completes)
# save arguments to pass to _add()
args = dict(
zip(['fixed', 'random', 'priors', 'family', 'link', 'categorical'],
[fixed, random, priors, family, link, categorical]))
self.added_terms.append(args)
self.built = False
def test_listify():
assert listify(None) == []
assert listify([1, 2, 3]) == [1, 2, 3]
assert listify("giraffe") == ["giraffe"]
def test_listify():
assert listify(None) == []
assert listify([1, 2, 3]) == [1, 2, 3]
assert listify('giraffe') == ['giraffe']
def add(self,
fixed=None,
random=None,
priors=None,
family='gaussian',
link=None,
categorical=None,
append=True):
'''
Adds one or more terms to the model via an R-like formula syntax.
Args:
fixed (str): Optional formula specification of fixed effects.
random (list): Optional list-based specification of random effects.
priors (dict): Optional specification of priors for one or more
terms. A dict where the keys are the names of terms in the
model, and the values are either instances of class Prior or
ints, floats, or strings that specify the width of the priors
on a standardized scale.
family (str, Family): A specification of the model family
(analogous to the family object in R). Either a string, or an
instance of class priors.Family. If a string is passed, a
family with the corresponding name must be defined in the
defaults loaded at Model initialization. Valid pre-defined
families are 'gaussian', 'bernoulli', 'poisson', and 't'.
link (str): The model link function to use. Can be either a string
(must be one of the options defined in the current backend;
typically this will include at least 'identity', 'logit',
'inverse', and 'log'), or a callable that takes a 1D ndarray
or theano tensor as the sole argument and returns one with
the same shape.
categorical (str, list): The names of any variables to treat as
categorical. Can be either a single variable name, or a list
of names. If categorical is None, the data type of the columns
in the DataFrame will be used to infer handling. In cases where
numeric columns are to be treated as categoricals (e.g., random
factors coded as numerical IDs), explicitly passing variable
names via this argument is recommended.
append (bool): if True, terms are appended to the existing model
rather than replacing any existing terms. This allows
formula-based specification of the model in stages.
'''
data = self.data
# Primitive values (floats, strs) can be overwritten with Prior objects
# so we need to make sure to copy first to avoid bad things happening
# if user is re-using same prior dict in multiple models.
if priors is None:
priors = {}
else:
priors = deepcopy(priors)
if not append:
self.reset()
# Explicitly convert columns to category if desired--though this
# can also be done within the formula using C().
if categorical is not None:
data = data.copy()
cats = listify(categorical)
data[cats] = data[cats].apply(lambda x: x.astype('category'))
if fixed is not None:
if '~' in fixed:
# check to see if formula is using the 'y[event] ~ x' syntax
# (for bernoulli models). If so, chop it into groups:
# 1 = 'y[event]', 2 = 'y', 3 = 'event', 4 = 'x'
# If this syntax is not being used, event = None
event = re.match(r'^((\S+)\[(\S+)\])\s*~(.*)$', fixed)
if event is not None:
fixed = '{}~{}'.format(event.group(2), event.group(4))
y, X = dmatrices(fixed, data=data, NA_action=Ignore_NA())
y_label = y.design_info.term_names[0]
if event is not None:
# pass in new Y data that has 1 if y=event and 0 otherwise
y_data = y[:,
y.design_info.column_names.index(event.group(1)
)]
y_data = pd.DataFrame({event.group(3): y_data})
self._add_y(y_label, family=family, link=link, data=y_data)
else:
# use Y as-is
self._add_y(y_label, family=family, link=link)
else:
X = dmatrix(fixed, data=data, NA_action=Ignore_NA())
# Loop over predictor terms
for _name, _slice in X.design_info.term_name_slices.items():
cols = X.design_info.column_names[_slice]
term_data = pd.DataFrame(X[:, _slice], columns=cols)
prior = priors.pop(_name, priors.get('fixed', None))
self.terms[_name] = Term(self, _name, term_data, prior=prior)
# Random effects
if random is not None:
random = listify(random)
for f in random:
f = f.strip()
# Split specification into intercept, predictor, and grouper
patt = r'^([01]+)*[\s\+]*([^\|]+)*\|(.*)'
intcpt, pred, grpr = re.search(patt, f).groups()
label = '{}|{}'.format(pred, grpr) if pred else grpr
prior = priors.pop(label, priors.get('random', None))
# Treat all grouping variables as categoricals, regardless of
# their dtype and what the user may have specified in the
# 'categorical' argument.
var_names = re.findall('(\w+)', grpr)
for v in var_names:
if v in data.columns:
data[v] = data.loc[:, v].astype('category')
self.data[v] = data[v]
# Default to including random intercepts
intcpt = 1 if intcpt is None else int(intcpt)
grpr_df = dmatrix('0+%s' % grpr,
data,
return_type='dataframe',
NA_action=Ignore_NA())
# If there's no predictor, we must be adding random intercepts
if not pred and grpr not in self.terms:
name = '1|' + grpr
pred = np.ones((len(grpr_df), 1))
term = RandomTerm(self,
name,
grpr_df,
pred,
grpr_df.values,
categorical=True,
prior=prior)
self.terms[name] = term
else:
pred_df = dmatrix('%s+%s' % (intcpt, pred),
data,
return_type='dataframe',
NA_action=Ignore_NA())
# determine value of the 'constant' attribute
const = np.atleast_2d(pred_df.T).T.sum(1).var() == 0
for col, i in pred_df.design_info.column_name_indexes.items(
):
pred_data = pred_df.iloc[:, i]
lev_data = grpr_df.multiply(pred_data, axis=0)
# Also rename intercepts and skip if already added.
# This can happen if user specifies something like
# random=['1|school', 'student|school'].
if col == 'Intercept':
if grpr in self.terms:
continue
label = '1|%s' % grpr
else:
label = col + '|' + grpr
prior = priors.pop(label, priors.get('random', None))
# Categorical or continuous is determined from data
ld = lev_data.values
if ((ld == 0) | (ld == 1)).all():
lev_data = lev_data.astype(int)
cat = True
else:
cat = False
pred_data = pred_data[:, None] # Must be 2D later
term = RandomTerm(self,
label,
lev_data,
pred_data,
grpr_df.values,
categorical=cat,
constant=const if const else None)
self.terms[label] = term
self.built = False
def add_formula(self,
fixed=None,
random=None,
priors=None,
family='gaussian',
link=None,
categorical=None,
append=False):
'''
Adds one or more terms to the model via an R-like formula syntax.
Args:
fixed (str): Optional formula specification of fixed effects.
random (list): Optional list-based specification of random effects.
priors (dict): Optional specification of priors for one or more
terms. A dict where the keys are the names of terms in the
model, and the values are either instances of class Prior or
ints, floats, or strings that specify the width of the priors
on a standardized scale.
family (str, Family): A specification of the model family
(analogous to the family object in R). Either a string, or an
instance of class priors.Family. If a string is passed, a
family with the corresponding name must be defined in the
defaults loaded at Model initialization. Valid pre-defined
families are 'gaussian', 'binomial', 'poisson', and 't'.
link (str): The model link function to use. Can be either a string
(must be one of the options defined in the current backend;
typically this will include at least 'identity', 'logit',
'inverse', and 'exp'), or a callable that takes a 1D ndarray
or theano tensor as the sole argument and returns one with
the same shape.
categorical (str, list): The names of any variables to treat as
categorical. Can be either a single variable name, or a list
of names. If categorical is None, the data type of the columns
in the DataFrame will be used to infer handling. In cases where
numeric columns are to be treated as categoricals (e.g., random
factors coded as numerical IDs), explicitly passing variable
names via this argument is recommended.
append (bool): if True, terms are appended to the existing model
rather than replacing any existing terms. This allows
formula-based specification of the model in stages.
'''
data = self.data
if priors is None:
priors = {}
if not append:
self.reset()
if fixed is not None:
# Explicitly convert columns to category if desired--though this
# can also be done within the formula using C().
if categorical is not None:
data = data.copy()
cats = listify(categorical)
data[cats] = data[cats].apply(lambda x: x.astype('category'))
if '~' in fixed:
y, X = dmatrices(fixed, data=data)
y_label = y.design_info.term_names[0]
self.add_y(y_label, family=family, link=link)
else:
X = dmatrix(fixed, data=data)
# Loop over predictor terms
for _name, _slice in X.design_info.term_name_slices.items():
cols = X.design_info.column_names[_slice]
term_data = pd.DataFrame(X[:, _slice], columns=cols)
prior = priors.pop(_name, priors.pop('fixed', None))
self.add_term(_name, data=term_data, prior=prior)
# Random effects
if random is not None:
random = listify(random)
for f in random:
f = f.strip()
kwargs = {'random': True}
if re.search('[\*\(\)]+', f):
raise ValueError("Random term '%s' contains an invalid "
"character. Note that only the | and + "
"operators are currently supported in "
"random effects specifications.")
# replace explicit intercept terms like '1|subj' with just 'subj'
f = re.sub(r'^1\s*\|(.*)', r'\1', f).strip()
# Split specification into intercept, predictor, and grouper
patt = r'^([01]+)*[\s\+]*([^\|]+)\|*(.*)'
intcpt, pred, grpr = re.search(patt, f).groups()
label = '{}|{}'.format(pred, grpr) if grpr else pred
# Default to including random intercepts
if intcpt is None:
intcpt = 1
intcpt = int(intcpt)
# If there's no grouper, we must be adding random intercepts
if not grpr:
kwargs.update(dict(categorical=True, drop_first=False))
variable = pred
else:
# If we're adding slopes, add random intercepts as well,
# unless they were explicitly excluded
if intcpt and grpr not in self.terms:
self.add_term(variable=grpr,
categorical=True,
random=True,
drop_first=False)
if self.data[pred].dtype.name in ['object', 'category']:
kwargs['categorical'] = True
if not intcpt:
kwargs['drop_first'] = False
variable, kwargs['over'] = pred, grpr
prior = priors.pop(label, priors.pop('random', None))
self.add_term(variable=variable, label=label, **kwargs)
