def symbol_map_from_instance(instance):
"""
Create a symbol map from an instance using name-based labelers.
"""
from pyomo.core.base import Var, Constraint, Objective
symbol_map = SymbolMap()
labeler = TextLabeler()
#
# Recursively iterate over all variables
#
for varvalue in instance.component_data_objects(Var, active=True):
symbol_map.getSymbol(varvalue, labeler)
#
# Recursively iterate over all constraints
#
for constraint_data in instance.component_data_objects(Constraint,
active=True):
con_symbol = symbol_map.getSymbol(constraint_data, labeler)
if constraint_data.equality:
label = 'c_e_%s_' % con_symbol
symbol_map.alias(constraint_data, label)
else:
if constraint_data.lower is not None:
if constraint_data.upper is not None:
symbol_map.alias(constraint_data, 'r_l_%s_' % con_symbol)
symbol_map.alias(constraint_data, 'r_u_%s_' % con_symbol)
else:
label = 'c_l_%s_' % con_symbol
symbol_map.alias(constraint_data, label)
elif constraint_data.upper is not None:
label = 'c_u_%s_' % con_symbol
symbol_map.alias(constraint_data, label)
#
# Recursively iterate over all objectives
#
first = True
for objective_data in instance.component_data_objects(Objective,
active=True):
symbol_map.getSymbol(objective_data, labeler)
if first:
# The first objective is the default
symbol_map.alias(objective_data, "__default_objective__")
first = False
#
# Return the symbol map
#
return symbol_map
def test_existing_alias(self):
s = SymbolMap()
v1 = variable()
s.alias(v1, "v")
self.assertIs(s.aliases["v"](), v1)
v2 = variable()
with self.assertRaises(RuntimeError):
s.alias(v2, "v")
s.alias(v1, "A")
self.assertIs(s.aliases["v"](), v1)
self.assertIs(s.aliases["A"](), v1)
s.alias(v1, "A")
self.assertIs(s.aliases["v"](), v1)
self.assertIs(s.aliases["A"](), v1)
def test_existing_alias(self):
s = SymbolMap()
v1 = variable()
s.alias(v1, "v")
self.assertIs(s.aliases["v"](), v1)
v2 = variable()
with self.assertRaises(RuntimeError):
s.alias(v2, "v")
s.alias(v1, "A")
self.assertIs(s.aliases["v"](), v1)
self.assertIs(s.aliases["A"](), v1)
s.alias(v1, "A")
self.assertIs(s.aliases["v"](), v1)
self.assertIs(s.aliases["A"](), v1)