def test_simple_substitute_param(self):
def diffeq(m, t, i):
return m.dxdt[t, i] == t * m.x[t, i - 1] ** 2 + m.y ** 2 + m.x[t, i + 1] + m.x[t, i - 1]
m = self.m
t = IndexTemplate(m.TIME)
e = diffeq(m, t, 2)
self.assertTrue(isinstance(e, EXPR._ExpressionBase))
_map = {}
E = substitute_template_expression(e, substitute_getitem_with_param, _map)
self.assertIsNot(e, E)
self.assertEqual(len(_map), 3)
idx1 = _GetItemIndexer(m.x[t, 1])
self.assertIs(idx1._base, m.x)
self.assertEqual(len(idx1._args), 2)
self.assertIs(idx1._args[0], t)
self.assertEqual(idx1._args[1], 1)
self.assertIn(idx1, _map)
idx2 = _GetItemIndexer(m.dxdt[t, 2])
self.assertIs(idx2._base, m.dxdt)
self.assertEqual(len(idx2._args), 2)
self.assertIs(idx2._args[0], t)
self.assertEqual(idx2._args[1], 2)
self.assertIn(idx2, _map)
idx3 = _GetItemIndexer(m.x[t, 3])
self.assertIs(idx3._base, m.x)
self.assertEqual(len(idx3._args), 2)
self.assertIs(idx3._args[0], t)
self.assertEqual(idx3._args[1], 3)
self.assertIn(idx3, _map)
self.assertFalse(idx1 == idx2)
self.assertFalse(idx1 == idx3)
self.assertFalse(idx2 == idx3)
idx4 = _GetItemIndexer(m.x[t, 2])
self.assertNotIn(idx4, _map)
t.set_value(5)
self.assertEqual((e._args[0](), e._args[1]()), (10, 136))
self.assertEqual(str(E), "dxdt[{TIME},2] == {TIME} * x[{TIME},1]**2.0 + y**2.0 + x[{TIME},3] + x[{TIME},1]")
_map[idx1].set_value(value(m.x[value(t), 1]))
_map[idx2].set_value(value(m.dxdt[value(t), 2]))
_map[idx3].set_value(value(m.x[value(t), 3]))
self.assertEqual((E._args[0](), E._args[1]()), (10, 136))
_map[idx1].set_value(12)
_map[idx2].set_value(34)
self.assertEqual((E._args[0](), E._args[1]()), (34, 738))
def test_substitute_casadi_intrinsic1(self):
m = self.m
m.y = Var()
t = IndexTemplate(m.t)
e = m.v[t]
templatemap = {}
e2 = substitute_template_expression(
e, substitute_getitem_with_casadi_sym, templatemap)
e3 = substitute_intrinsic_function(
e2, substitute_intrinsic_function_with_casadi)
self.assertIs(type(e3), casadi.SX)
m.del_component('y')
def test_substitute_casadi_intrinsic3(self):
m = self.m
m.y = Var()
t = IndexTemplate(m.t)
e = sin(m.dv[t] + m.v[t]) + log(m.v[t] * m.y + m.dv[t]**2)
templatemap = {}
e2 = substitute_template_expression(
e, substitute_getitem_with_casadi_sym, templatemap)
e3 = substitute_intrinsic_function(
e2, substitute_intrinsic_function_with_casadi)
self.assertIs(e3._args[0]._operator, casadi.sin)
self.assertIs(e3._args[1]._operator, casadi.log)
m.del_component('y')
def test_simple_substitute_index(self):
def diffeq(m, t, i):
return m.dxdt[t, i] == t * m.x[t, i]**2 + m.y**2
m = self.m
t = IndexTemplate(m.TIME)
e = diffeq(m, t, 2)
t.set_value(5)
self.assertTrue(isinstance(e, EXPR._ExpressionBase))
self.assertEqual((e._args[0](), e._args[1]()), (10, 126))
E = substitute_template_expression(e, substitute_template_with_value)
self.assertIsNot(e, E)
self.assertEqual(str(E), 'dxdt[5,2] == 5.0 * x[5,2]**2.0 + y**2.0')
def test_simple_substitute_index(self):
def diffeq(m, t, i):
return m.dxdt[t, i] == t * m.x[t, i] ** 2 + m.y ** 2
m = self.m
t = IndexTemplate(m.TIME)
e = diffeq(m, t, 2)
t.set_value(5)
self.assertTrue(isinstance(e, EXPR._ExpressionBase))
self.assertEqual((e._args[0](), e._args[1]()), (10, 126))
E = substitute_template_expression(e, substitute_template_with_value)
self.assertIsNot(e, E)
self.assertEqual(str(E), "dxdt[5,2] == 5.0 * x[5,2]**2.0 + y**2.0")
def test_substitute_casadi_sym(self):
m = self.m
m.y = Var()
t = IndexTemplate(m.t)
e = m.dv[t] + m.v[t] + m.y + t
templatemap = {}
e2 = substitute_template_expression(
e, substitute_getitem_with_casadi_sym, templatemap)
self.assertEqual(len(templatemap), 2)
self.assertIs(type(e2._args[0]), casadi.SX)
self.assertIs(type(e2._args[1]), casadi.SX)
self.assertIsNot(type(e2._args[2]), casadi.SX)
self.assertIs(type(e2._args[3]), IndexTemplate)
m.del_component('y')
def test_substitute_casadi_intrinsic4(self):
m = self.m
m.y = Var()
t = IndexTemplate(m.t)
e = m.v[t] * sin(m.dv[t] + m.v[t]) * t
templatemap = {}
e2 = substitute_template_expression(
e, substitute_getitem_with_casadi_sym, templatemap)
e3 = substitute_intrinsic_function(
e2, substitute_intrinsic_function_with_casadi)
self.assertIs(type(e3._numerator[0]), casadi.SX)
self.assertIs(e3._numerator[1]._operator, casadi.sin)
self.assertIs(type(e3._numerator[2]), IndexTemplate)
m.del_component('y')
def test_simple_substitute_param(self):
def diffeq(m, t, i):
return m.dxdt[t, i] == t*m.x[t, i-1]**2 + m.y**2 + \
m.x[t, i+1] + m.x[t, i-1]
m = self.m
t = IndexTemplate(m.TIME)
e = diffeq(m, t, 2)
self.assertTrue(isinstance(e, EXPR._ExpressionBase))
_map = {}
E = substitute_template_expression(e, substitute_getitem_with_param,
_map)
self.assertIsNot(e, E)
self.assertEqual(len(_map), 3)
idx1 = _GetItemIndexer(m.x[t, 1])
self.assertIs(idx1._base, m.x)
self.assertEqual(len(idx1._args), 2)
self.assertIs(idx1._args[0], t)
self.assertEqual(idx1._args[1], 1)
self.assertIn(idx1, _map)
idx2 = _GetItemIndexer(m.dxdt[t, 2])
self.assertIs(idx2._base, m.dxdt)
self.assertEqual(len(idx2._args), 2)
self.assertIs(idx2._args[0], t)
self.assertEqual(idx2._args[1], 2)
self.assertIn(idx2, _map)
idx3 = _GetItemIndexer(m.x[t, 3])
self.assertIs(idx3._base, m.x)
self.assertEqual(len(idx3._args), 2)
self.assertIs(idx3._args[0], t)
self.assertEqual(idx3._args[1], 3)
self.assertIn(idx3, _map)
self.assertFalse(idx1 == idx2)
self.assertFalse(idx1 == idx3)
self.assertFalse(idx2 == idx3)
idx4 = _GetItemIndexer(m.x[t, 2])
self.assertNotIn(idx4, _map)
t.set_value(5)
self.assertEqual((e._args[0](), e._args[1]()), (10, 136))
self.assertEqual(
str(E),
'dxdt[{TIME},2] == {TIME} * x[{TIME},1]**2.0 + y**2.0 + x[{TIME},3] + x[{TIME},1]'
)
_map[idx1].set_value(value(m.x[value(t), 1]))
_map[idx2].set_value(value(m.dxdt[value(t), 2]))
_map[idx3].set_value(value(m.x[value(t), 3]))
self.assertEqual((E._args[0](), E._args[1]()), (10, 136))
_map[idx1].set_value(12)
_map[idx2].set_value(34)
self.assertEqual((E._args[0](), E._args[1]()), (34, 738))
def __init__(self, m, package='scipy'):
self._intpackage = package
if self._intpackage not in ['scipy', 'casadi']:
raise DAE_Error(
"Unrecognized simulator package %s. Please select from "
"%s" % (self._intpackage, ['scipy', 'casadi']))
if self._intpackage == 'scipy':
if not scipy_available:
# Converting this to a warning so that Simulator initialization
# can be tested even when scipy is unavailable
logger.warning("The scipy module is not available. You may "
"build the Simulator object but you will not "
"be able to run the simulation.")
substituter = substitute_getitem_with_param
else:
if not casadi_available:
# Initializing the simulator for use with casadi requires
# access to casadi objects. Therefore, we must throw an error
# here instead of a warning.
raise ValueError("The casadi module is not available. "
"Cannot simulate model.")
substituter = substitute_getitem_with_casadi_sym
# Check for active Blocks and throw error if any are found
if len(list(m.component_data_objects(Block, active=True,
descend_into=False))):
raise DAE_Error("The Simulator cannot handle hierarchical models "
"at the moment.")
temp = m.component_map(ContinuousSet)
if len(temp) != 1:
raise DAE_Error(
"Currently the simulator may only be applied to "
"Pyomo models with a single ContinuousSet")
# Get the ContinuousSet in the model
contset = list(temp.values())[0]
# Create a index template for the continuous set
cstemplate = IndexTemplate(contset)
# Ensure that there is at least one derivative in the model
derivs = m.component_map(DerivativeVar)
if len(derivs) == 0:
raise DAE_Error("Cannot simulate a model with no derivatives")
templatemap = {} # Map for template substituter
rhsdict = {} # Map of derivative to its RHS templated expr
derivlist = [] # Ordered list of derivatives
alglist = [] # list of templated algebraic equations
# Loop over constraints to find differential equations with separable
# RHS. Must find a RHS for every derivative var otherwise ERROR. Build
# dictionary of DerivativeVar:RHS equation.
for con in m.component_objects(Constraint, active=True):
# Skip the discretization equations if model is discretized
if '_disc_eq' in con.name:
continue
# Check dimension of the Constraint. Check if the
# Constraint is indexed by the continuous set and
# determine its order in the indexing sets
if con.dim() == 0:
continue
elif con._implicit_subsets is None:
# Check if the continuous set is the indexing set
if con._index is not contset:
continue
else:
csidx = 0
noncsidx = (None,)
else:
temp = con._implicit_subsets
dimsum = 0
csidx = -1
noncsidx = None
for s in temp:
if s is contset:
if csidx != -1:
raise DAE_Error(
"Cannot simulate the constraint %s because "
"it is indexed by duplicate ContinuousSets"
% con.name)
csidx = dimsum
elif noncsidx is None:
noncsidx = s
else:
noncsidx = noncsidx.cross(s)
dimsum += s.dimen
if csidx == -1:
continue
# Get the rule used to construct the constraint
conrule = con.rule
for i in noncsidx:
# Insert the index template and call the rule to
# create a templated expression
if i is None:
tempexp = conrule(m, cstemplate)
else:
if not isinstance(i, tuple):
i = (i,)
tempidx = i[0:csidx] + (cstemplate,) + i[csidx:]
tempexp = conrule(m, *tempidx)
# Check to make sure it's an _EqualityExpression
if not type(tempexp) is EXPR._EqualityExpression:
continue
# Check to make sure it's a differential equation with
# separable RHS
args = None
# Case 1: m.dxdt[t] = RHS
if type(tempexp._args[0]) is EXPR._GetItemExpression:
args = _check_getitemexpression(tempexp, 0)
# Case 2: RHS = m.dxdt[t]
if args is None:
if type(tempexp._args[1]) is EXPR._GetItemExpression:
args = _check_getitemexpression(tempexp, 1)
# Case 3: m.p*m.dxdt[t] = RHS
if args is None:
if type(tempexp._args[0]) is EXPR._ProductExpression:
args = _check_productexpression(tempexp, 0)
# Case 4: RHS = m.p*m.dxdt[t]
if args is None:
if type(tempexp._args[1]) is EXPR._ProductExpression:
args = _check_productexpression(tempexp, 1)
# Case 5: m.dxdt[t] + CONSTANT = RHS
# or CONSTANT + m.dxdt[t] = RHS
if args is None:
if type(tempexp._args[0]) is EXPR._SumExpression:
args = _check_sumexpression(tempexp, 0)
# Case 6: RHS = m.dxdt[t] + CONSTANT
if args is None:
if type(tempexp._args[1]) is EXPR._SumExpression:
args = _check_sumexpression(tempexp, 1)
# Case 7: RHS = m.p*m.dxdt[t] + CONSTANT
# This case will be caught by Case 6 if p is immutable. If
# p is mutable then this case will not be detected as a
# separable differential equation
# At this point if args is not None then args[0] contains
# the _GetItemExpression for the DerivativeVar and args[1]
# contains the RHS expression. If args is None then the
# constraint is considered an algebraic equation
if args is None:
# Constraint is an algebraic equation or unsupported
# differential equation
if self._intpackage == 'scipy':
raise DAE_Error(
"Model contains an algebraic equation or "
"unrecognized differential equation. Constraint "
"'%s' cannot be simulated using Scipy. If you are "
"trying to simulate a DAE model you must use "
"CasADi as the integration package."
% str(con.name))
tempexp = tempexp._args[0] - tempexp._args[1]
algexp = substitute_template_expression(tempexp,
substituter,
templatemap)
algexp = substitute_intrinsic_function(
algexp, substitute_intrinsic_function_with_casadi)
alglist.append(algexp)
continue
# Add the differential equation to rhsdict and derivlist
dv = args[0]
RHS = args[1]
dvkey = _GetItemIndexer(dv)
if dvkey in rhsdict.keys():
raise DAE_Error(
"Found multiple RHS expressions for the "
"DerivativeVar %s" % str(dvkey))
derivlist.append(dvkey)
tempexp = substitute_template_expression(
RHS, substituter, templatemap)
if self._intpackage is 'casadi':
# After substituting GetItemExpression objects
# replace intrinsic Pyomo functions with casadi
# functions
tempexp = substitute_intrinsic_function(
tempexp, substitute_intrinsic_function_with_casadi)
rhsdict[dvkey] = tempexp
# Check to see if we found a RHS for every DerivativeVar in
# the model
# FIXME: Not sure how to rework this for multi-index case
# allderivs = derivs.keys()
# if set(allderivs) != set(derivlist):
# missing = list(set(allderivs)-set(derivlist))
# print("WARNING: Could not find a RHS expression for the "
# "following DerivativeVar components "+str(missing))
# Create ordered list of differential variables corresponding
# to the list of derivatives.
diffvars = []
for deriv in derivlist:
sv = deriv._base.get_state_var()
diffvars.append(_GetItemIndexer(sv[deriv._args]))
# Create ordered list of algebraic variables and time-varying
# parameters
algvars = []
for item in iterkeys(templatemap):
if item._base.name in derivs.keys():
# Make sure there are no DerivativeVars in the
# template map
raise DAE_Error(
"Cannot simulate a differential equation with "
"multiple DerivativeVars")
if item not in diffvars:
# Finds time varying parameters and algebraic vars
algvars.append(item)
if self._intpackage == 'scipy':
# Function sent to scipy integrator
def _rhsfun(t, x):
residual = []
cstemplate.set_value(t)
for idx, v in enumerate(diffvars):
if v in templatemap:
templatemap[v].set_value(x[idx])
for d in derivlist:
residual.append(rhsdict[d]())
return residual
self._rhsfun = _rhsfun
self._contset = contset
self._cstemplate = cstemplate
self._diffvars = diffvars
self._derivlist = derivlist
self._templatemap = templatemap
self._rhsdict = rhsdict
self._alglist = alglist
self._algvars = algvars
self._model = m
self._tsim = None
self._simsolution = None
# The algebraic vars in the most recent simulation
self._simalgvars = None
# The time-varying inputs in the most recent simulation
self._siminputvars = None