def testConstraint(self):
"""Test the Constraint class."""
p1 = Parameter("p1", 1)
p2 = Parameter("p2", 2)
factory = EquationFactory()
factory.registerArgument("p1", p1)
factory.registerArgument("p2", p2)
c = Constraint()
# Constrain p1 = 2*p2
eq = equationFromString("2*p2", factory)
c.constrain(p1, eq)
self.assertTrue(p1.constrained)
self.assertFalse(p2.constrained)
eq2 = equationFromString("2*p2+1", factory)
c2 = Constraint()
self.assertRaises(ValueError, c2.constrain, p1, eq2)
p2.setConst()
eq3 = equationFromString("p1", factory)
self.assertRaises(ValueError, c2.constrain, p2, eq3)
p2.setValue(2.5)
c.update()
self.assertEquals(5.0, p1.getValue())
p2.setValue(8.1)
self.assertEquals(5.0, p1.getValue())
c.update()
self.assertEquals(16.2, p1.getValue())
return
def constrain(self, par, con, ns={}):
"""Constrain a parameter to an equation.
Note that only one constraint can exist on a Parameter at a time.
par -- The name of a Parameter or a Parameter to constrain.
con -- A string representation of the constraint equation or a
Parameter to constrain to. A constraint equation must
consist of numpy operators and "known" Parameters.
Parameters are known if they are in the ns argument, or if
they are managed by this object.
ns -- A dictionary of Parameters, indexed by name, that are used
in the parameter, but not part of this object (default {}).
Raises ValueError if ns uses a name that is already used for a
variable.
Raises ValueError if par is a string but not part of this object or in
ns.
Raises ValueError if par is marked as constant.
"""
if isinstance(par, basestring):
name = par
par = self.get(name)
if par is None:
par = ns.get(name)
if par is None:
raise ValueError("The parameter cannot be found")
if par.const:
raise ValueError("The parameter '%s' is constant" % par)
if isinstance(con, basestring):
eqstr = con
eq = equationFromString(con, self._eqfactory, ns)
else:
eq = Equation(root=con)
eqstr = con.name
eq.name = "_constraint_%s" % par.name
# Make and store the constraint
con = Constraint()
con.constrain(par, eq)
# Store the equation string so it can be shown later.
con.eqstr = eqstr
self._constraints[par] = con
# Our configuration changed
self._updateConfiguration()
return
def constrain(self, par, con, ns={}):
"""Constrain a parameter to an equation.
Note that only one constraint can exist on a Parameter at a time.
par -- The name of a Parameter or a Parameter to constrain.
con -- A string representation of the constraint equation or a
Parameter to constrain to. A constraint equation must
consist of numpy operators and "known" Parameters.
Parameters are known if they are in the ns argument, or if
they are managed by this object.
ns -- A dictionary of Parameters, indexed by name, that are used
in the parameter, but not part of this object (default {}).
Raises ValueError if ns uses a name that is already used for a
variable.
Raises ValueError if par is a string but not part of this object or in
ns.
Raises ValueError if par is marked as constant.
"""
if isinstance(par, basestring):
name = par
par = self.get(name)
if par is None:
par = ns.get(name)
if par is None:
raise ValueError("The parameter cannot be found")
if par.const:
raise ValueError("The parameter '%s' is constant" % par)
if isinstance(con, basestring):
eqstr = con
eq = equationFromString(con, self._eqfactory, ns)
else:
eq = Equation(root=con)
eqstr = con.name
eq.name = "_constraint_%s" % par.name
# Make and store the constraint
con = Constraint()
con.constrain(par, eq)
# Store the equation string so it can be shown later.
con.eqstr = eqstr
self._constraints[par] = con
# Our configuration changed
self._updateConfiguration()
return
def testConstraint(self):
"""Test the Constraint class."""
p1 = Parameter("p1", 1)
p2 = Parameter("p2", 2)
factory = EquationFactory()
factory.registerArgument("p1", p1)
factory.registerArgument("p2", p2)
c = Constraint()
# Constrain p1 = 2*p2
eq = equationFromString("2*p2", factory)
c.constrain(p1, eq)
self.assertTrue(p1.constrained)
self.assertFalse(p2.constrained)
eq2 = equationFromString("2*p2+1", factory)
c2 = Constraint()
self.assertRaises(ValueError, c2.constrain, p1, eq2)
p2.setConst()
eq3 = equationFromString("p1", factory)
self.assertRaises(ValueError, c2.constrain, p2, eq3)
p2.setValue(2.5)
c.update()
self.assertEquals(5.0, p1.getValue())
p2.setValue(8.1)
self.assertEquals(5.0, p1.getValue())
c.update()
self.assertEquals(16.2, p1.getValue())
return
