def parse_formula(code, extra_operators=[]):
if not code.strip():
code = "~ 1"
for op in extra_operators:
if op.precedence < 0:
raise ValueError, "all operators must have precedence >= 0"
operators = _default_ops + extra_operators
operator_strings = [op.token_type for op in operators]
tree = infix_parse(_tokenize_formula(code, operator_strings), operators, _atomic_token_types)
if not isinstance(tree, ParseNode) or tree.type != "~":
tree = ParseNode("~", None, [tree], tree.origin)
return tree
def parse_formula(code, extra_operators=[]):
if not code.strip():
code = "~ 1"
for op in extra_operators:
if op.precedence < 0:
raise ValueError, "all operators must have precedence >= 0"
operators = _default_ops + extra_operators
operator_strings = [op.token_type for op in operators]
tree = infix_parse(_tokenize_formula(code, operator_strings), operators,
_atomic_token_types)
if not isinstance(tree, ParseNode) or tree.type != "~":
tree = ParseNode("~", None, [tree], tree.origin)
return tree
def evaluate_formula(formula):
"""Given mixed effects formula, return a model description."""
# mixed effects specific operators
extra_operators = [Operator('|', 2, 50), Operator('|| ', 2, 50)]
# construct a list of operator strings needed for tokenization
operators = _default_ops + extra_operators
operator_strings = [op.token_type for op in operators]
tokens = list(_tokenize_formula(formula, operator_strings))
node = infix_parse(tokens, operators, _atomic_token_types)
e = Evaluator()
# we can't handle double bar yet
e.add_op('|', 2, eval_bar)
model_description = e.eval(node, require_evalexpr=False)
return model_description
def parse_constraint(string, variable_names):
return infix_parse(_tokenize_constraint(string, variable_names),
_ops, _atomic)
def parse_constraint(string, variable_names):
return infix_parse(_tokenize_constraint(string, variable_names),
_ops, _atomic)
def _query_from_string(events, string):
return _eval(events, infix_parse(_tokenize(string), _ops, _atomic))
def _query_from_string(events, string):
return _eval(events, infix_parse(_tokenize(string), _ops, _atomic))
