def test_change_of_objective_is_reflected_in_low_level_solver(self):
x = Variable('x', lb=-83.3, ub=1324422.)
y = Variable('y', lb=-181133.3, ub=12000.)
objective = Objective(0.3 * x + 0.4 * y, name='test', direction='max')
self.model.objective = objective
self.assertEqual((self.model.objective.expression -
(0.4 * y + 0.3 * x)).expand() - 0, 0)
self.assertEqual(self.model.objective.direction, "max")
self.assertEqual(glp_get_obj_coef(self.model.problem, x._index), 0.3)
self.assertEqual(glp_get_obj_coef(self.model.problem, y._index), 0.4)
for i in range(1, glp_get_num_cols(self.model.problem) + 1):
if i != x._index and i != y._index:
self.assertEqual(glp_get_obj_coef(self.model.problem, i), 0)
z = Variable('z', lb=4, ub=4, type='integer')
self.model.objective += 77. * z
self.assertEqual((self.model.objective.expression -
(0.4 * y + 0.3 * x + 77.0 * z)).expand() - 0, 0)
self.assertEqual(self.model.objective.direction, "max")
self.assertEqual(glp_get_obj_coef(self.model.problem, x._index), 0.3)
self.assertEqual(glp_get_obj_coef(self.model.problem, y._index), 0.4)
self.assertEqual(glp_get_obj_coef(self.model.problem, z._index), 77.)
for i in range(1, glp_get_num_cols(self.model.problem) + 1):
if i != x._index and i != y._index and i != z._index:
self.assertEqual(glp_get_obj_coef(self.model.problem, i), 0)
def test_change_of_objective_is_reflected_in_low_level_solver(self):
x = self.interface.Variable('x', lb=-83.3, ub=1324422.)
y = self.interface.Variable('y', lb=-181133.3, ub=12000.)
objective = self.interface.Objective(0.3 * x + 0.4 * y, name='test', direction='max')
self.model.objective = objective
self.assertEqual(
(self.model.objective.expression - (0.4 * y + 0.3 * x)).expand() - 0, 0
)
self.assertEqual(self.model.objective.direction, "max")
self.assertEqual(glp_get_obj_coef(self.model.problem, x._index), 0.3)
self.assertEqual(glp_get_obj_coef(self.model.problem, y._index), 0.4)
for i in range(1, glp_get_num_cols(self.model.problem) + 1):
if i != x._index and i != y._index:
self.assertEqual(glp_get_obj_coef(self.model.problem, i), 0)
z = self.interface.Variable('z', lb=4, ub=4, type='integer')
self.model.objective += 77. * z
self.assertEqual(
(self.model.objective.expression - (0.4 * y + 0.3 * x + 77.0 * z)).expand() - 0, 0
)
self.assertEqual(self.model.objective.direction, "max")
self.assertEqual(glp_get_obj_coef(self.model.problem, x._index), 0.3)
self.assertEqual(glp_get_obj_coef(self.model.problem, y._index), 0.4)
self.assertEqual(glp_get_obj_coef(self.model.problem, z._index), 77.)
for i in range(1, glp_get_num_cols(self.model.problem) + 1):
if i != x._index and i != y._index and i != z._index:
self.assertEqual(glp_get_obj_coef(self.model.problem, i), 0)
def test_init_from_existing_problem(self):
inner_prob = self.model.problem
self.assertEqual(len(self.model.variables), glp_get_num_cols(inner_prob))
self.assertEqual(len(self.model.constraints), glp_get_num_rows(inner_prob))
self.assertEqual(self.model.variables.keys(),
[glp_get_col_name(inner_prob, i) for i in range(1, glp_get_num_cols(inner_prob) + 1)])
self.assertEqual(self.model.constraints.keys(),
[glp_get_row_name(inner_prob, j) for j in range(1, glp_get_num_rows(inner_prob) + 1)])
def test_change_variable_bounds(self):
inner_prob = self.model.problem
inner_problem_bounds = [(glp_get_col_lb(inner_prob, i), glp_get_col_ub(inner_prob, i)) for i in
range(1, glp_get_num_cols(inner_prob) + 1)]
bounds = [(var.lb, var.ub) for var in self.model.variables.values()]
self.assertEqual(bounds, inner_problem_bounds)
for var in self.model.variables.values():
var.lb = random.uniform(-1000, 1000)
var.ub = random.uniform(var.lb, 1000)
inner_problem_bounds_new = [(glp_get_col_lb(inner_prob, i), glp_get_col_ub(inner_prob, i)) for i in
range(1, glp_get_num_cols(inner_prob) + 1)]
bounds_new = [(var.lb, var.ub) for var in self.model.variables.values()]
self.assertNotEqual(bounds, bounds_new)
self.assertNotEqual(inner_problem_bounds, inner_problem_bounds_new)
self.assertEqual(bounds_new, inner_problem_bounds_new)
def test_init_from_existing_problem(self):
inner_prob = self.model.problem
self.assertEqual(len(self.model.variables),
glp_get_num_cols(inner_prob))
self.assertEqual(len(self.model.constraints),
glp_get_num_rows(inner_prob))
self.assertEqual(self.model.variables.keys(), [
glp_get_col_name(inner_prob, i)
for i in range(1,
glp_get_num_cols(inner_prob) + 1)
])
self.assertEqual(self.model.constraints.keys(), [
glp_get_row_name(inner_prob, j)
for j in range(1,
glp_get_num_rows(inner_prob) + 1)
])
def set_linear_coefficients(self, coefficients):
if self.problem is not None:
problem = self.problem.problem
self.problem.update()
num_cols = glp_get_num_cols(problem)
ia = intArray(num_cols + 1)
va = doubleArray(num_cols + 1)
num_rows = glp_get_mat_row(self.problem.problem, self._index, ia, va)
variables_and_coefficients = {var.name: coeff for var, coeff in six.iteritems(coefficients)}
final_variables_and_coefficients = {
glp_get_col_name(problem, ia[i]): va[i] for i in range(1, num_rows + 1)
}
final_variables_and_coefficients.update(variables_and_coefficients)
ia = intArray(num_cols + 1)
va = doubleArray(num_cols + 1)
for i, (name, coeff) in enumerate(six.iteritems(final_variables_and_coefficients)):
ia[i + 1] = self.problem._variables[name]._index
va[i + 1] = float(coeff)
glp_set_mat_row(problem, self._index, len(final_variables_and_coefficients), ia, va)
else:
raise Exception("Can't change coefficients if constraint is not associated with a model.")
def set_linear_coefficients(self, coefficients):
if self.problem is not None:
problem = self.problem.problem
num_cols = glp_get_num_cols(problem)
ia = intArray(num_cols + 1)
va = doubleArray(num_cols + 1)
num_rows = glp_get_mat_row(self.problem.problem, self._index, ia, va)
variables_and_coefficients = {var.name: coeff for var, coeff in six.iteritems(coefficients)}
final_variables_and_coefficients = {
glp_get_col_name(problem, ia[i]): va[i] for i in range(1, num_rows + 1)
}
final_variables_and_coefficients.update(variables_and_coefficients)
ia = intArray(num_cols + 1)
va = doubleArray(num_cols + 1)
for i, (name, coeff) in enumerate(six.iteritems(final_variables_and_coefficients)):
ia[i + 1] = self.problem._variables[name]._index
va[i + 1] = coeff
glp_set_mat_row(problem, self._index, len(final_variables_and_coefficients), ia, va)
else:
raise Exception("Can't change coefficients if constraint is not associated with a model.")
def _add_variables(self, variables):
for variable in variables:
glp_add_cols(self.problem, 1)
index = glp_get_num_cols(self.problem)
glp_set_col_name(self.problem, index, str(variable.name))
variable.problem = self
self._glpk_set_col_bounds(variable)
glp_set_col_kind(self.problem, variable.index, _VTYPE_TO_GLPK_VTYPE[variable.type])
super(Model, self)._add_variables(variables)
def _add_variables(self, variables):
for variable in variables:
glp_add_cols(self.problem, 1)
index = glp_get_num_cols(self.problem)
glp_set_col_name(self.problem, index, str(variable.name))
variable.problem = self
self._glpk_set_col_bounds(variable)
glp_set_col_kind(self.problem, variable._index, _VTYPE_TO_GLPK_VTYPE[variable.type])
super(Model, self)._add_variables(variables)
def get_num_cols(self):
'get the number of columns in the lp'
cols = glpk.glp_get_num_cols(self.lp)
assert cols == len(
self.names
), f"lp had {cols} columns, but names list had {len(self.names)} names"
return cols
def get_clocks(problem: SwigPyObject) -> Iterable[Tuple[str, float]]:
n_recipes = 0
for j in range(1, 1 + lp.glp_get_num_cols(problem)):
clock = lp.glp_mip_col_val(problem, j)
if clock:
name = lp.glp_get_col_name(problem, j)
yield name, clock
n_recipes += 1
logger.info(f'{n_recipes} recipes in rate solution.')
def test_set_linear_coefficients_constraint(self):
constraint = self.model.constraints.M_atp_c
constraint.set_linear_coefficients({self.model.variables.R_Biomass_Ecoli_core_w_GAM: 666.})
num_cols = glp_get_num_cols(self.model.problem)
ia = intArray(num_cols + 1)
da = doubleArray(num_cols + 1)
index = constraint._index
num = glp_get_mat_row(self.model.problem, index, ia, da)
for i in range(1, num + 1):
col_name = glp_get_col_name(self.model.problem, ia[i])
if col_name == 'R_Biomass_Ecoli_core_w_GAM':
self.assertEqual(da[i], 666.)
def _get_expression(self):
if self.problem is not None:
col_num = glp_get_num_cols(self.problem.problem)
ia = intArray(col_num + 1)
da = doubleArray(col_num + 1)
nnz = glp_get_mat_row(self.problem.problem, self.index, ia, da)
constraint_variables = [self.problem._variables[glp_get_col_name(self.problem.problem, ia[i])] for i in
range(1, nnz + 1)]
expression = sympy.Add._from_args(
[sympy.Mul._from_args((sympy.RealNumber(da[i]), constraint_variables[i - 1])) for i in
range(1, nnz + 1)])
self._expression = expression
return self._expression
def _get_expression(self):
if self.problem is not None:
col_num = glp_get_num_cols(self.problem.problem)
ia = intArray(col_num + 1)
da = doubleArray(col_num + 1)
nnz = glp_get_mat_row(self.problem.problem, self._index, ia, da)
constraint_variables = [self.problem._variables[glp_get_col_name(self.problem.problem, ia[i])] for i in
range(1, nnz + 1)]
expression = symbolics.add(
[symbolics.mul((symbolics.Real(da[i]), constraint_variables[i - 1])) for i in
range(1, nnz + 1)])
self._expression = expression
return self._expression
def test_set_linear_coefficients_constraint(self):
constraint = self.model.constraints.M_atp_c
constraint.set_linear_coefficients(
{self.model.variables.R_Biomass_Ecoli_core_w_GAM: 666.})
num_cols = glp_get_num_cols(self.model.problem)
ia = intArray(num_cols + 1)
da = doubleArray(num_cols + 1)
index = constraint._index
num = glp_get_mat_row(self.model.problem, index, ia, da)
for i in range(1, num + 1):
col_name = glp_get_col_name(self.model.problem, ia[i])
if col_name == 'R_Biomass_Ecoli_core_w_GAM':
self.assertEqual(da[i], 666.)
def _get_expression(self):
if self.problem is not None:
col_num = glp_get_num_cols(self.problem.problem)
ia = intArray(col_num + 1)
da = doubleArray(col_num + 1)
nnz = glp_get_mat_row(self.problem.problem, self._index, ia, da)
constraint_variables = [self.problem._variables[glp_get_col_name(self.problem.problem, ia[i])] for i in
range(1, nnz + 1)]
expression = symbolics.add(
[symbolics.mul((symbolics.Real(da[i]), constraint_variables[i - 1])) for i in
range(1, nnz + 1)])
self._expression = expression
return self._expression
def test_change_variable_bounds(self):
inner_prob = self.model.problem
inner_problem_bounds = [
(glp_get_col_lb(inner_prob, i), glp_get_col_ub(inner_prob, i))
for i in range(1,
glp_get_num_cols(inner_prob) + 1)
]
bounds = [(var.lb, var.ub) for var in self.model.variables.values()]
self.assertEqual(bounds, inner_problem_bounds)
for var in self.model.variables.values():
var.lb = random.uniform(-1000, 1000)
var.ub = random.uniform(var.lb, 1000)
inner_problem_bounds_new = [
(glp_get_col_lb(inner_prob, i), glp_get_col_ub(inner_prob, i))
for i in range(1,
glp_get_num_cols(inner_prob) + 1)
]
bounds_new = [(var.lb, var.ub)
for var in self.model.variables.values()]
self.assertNotEqual(bounds, bounds_new)
self.assertNotEqual(inner_problem_bounds, inner_problem_bounds_new)
self.assertEqual(bounds_new, inner_problem_bounds_new)
def solve_with_glpsol(glp_prob):
"""Solve glpk problem with glpsol commandline solver. Mainly for testing purposes.
# Examples
# --------
# >>> problem = glp_create_prob()
# ... glp_read_lp(problem, None, "../tests/data/model.lp")
# ... solution = solve_with_glpsol(problem)
# ... print 'asdf'
# 'asdf'
# >>> print solution
# 0.839784
# Returns
# -------
# dict
# A dictionary containing the objective value (key ='objval')
# and variable primals.
"""
from swiglpk import glp_get_row_name, glp_get_col_name, glp_write_lp, glp_get_num_rows, glp_get_num_cols
row_ids = [glp_get_row_name(glp_prob, i) for i in range(1, glp_get_num_rows(glp_prob) + 1)]
col_ids = [glp_get_col_name(glp_prob, i) for i in range(1, glp_get_num_cols(glp_prob) + 1)]
with tempfile.NamedTemporaryFile(suffix=".lp", delete=True) as tmp_file:
tmp_file_name = tmp_file.name
glp_write_lp(glp_prob, None, tmp_file_name)
cmd = ['glpsol', '--lp', tmp_file_name, '-w', tmp_file_name + '.sol', '--log', '/dev/null']
term = check_output(cmd)
log.info(term)
try:
with open(tmp_file_name + '.sol') as sol_handle:
# print sol_handle.read()
solution = dict()
for i, line in enumerate(sol_handle.readlines()):
if i <= 1 or line == '\n':
pass
elif i <= len(row_ids):
solution[row_ids[i - 2]] = line.strip().split(' ')
elif i <= len(row_ids) + len(col_ids) + 1:
solution[col_ids[i - 2 - len(row_ids)]] = line.strip().split(' ')
else:
print(i)
print(line)
raise Exception("Argggh!")
finally:
os.remove(tmp_file_name + ".sol")
return solution
def solve_with_glpsol(glp_prob):
"""Solve glpk problem with glpsol commandline solver. Mainly for testing purposes.
# Examples
# --------
# >>> problem = glp_create_prob()
# ... glp_read_lp(problem, None, "../tests/data/model.lp")
# ... solution = solve_with_glpsol(problem)
# ... print 'asdf'
# 'asdf'
# >>> print solution
# 0.839784
# Returns
# -------
# dict
# A dictionary containing the objective value (key ='objval')
# and variable primals.
"""
from swiglpk import glp_get_row_name, glp_get_col_name, glp_write_lp, glp_get_num_rows, glp_get_num_cols
row_ids = [glp_get_row_name(glp_prob, i) for i in range(1, glp_get_num_rows(glp_prob) + 1)]
col_ids = [glp_get_col_name(glp_prob, i) for i in range(1, glp_get_num_cols(glp_prob) + 1)]
with tempfile.NamedTemporaryFile(suffix=".lp", delete=True) as tmp_file:
tmp_file_name = tmp_file.name
glp_write_lp(glp_prob, None, tmp_file_name)
cmd = ['glpsol', '--lp', tmp_file_name, '-w', tmp_file_name + '.sol', '--log', '/dev/null']
term = check_output(cmd)
log.info(term)
try:
with open(tmp_file_name + '.sol') as sol_handle:
# print sol_handle.read()
solution = dict()
for i, line in enumerate(sol_handle.readlines()):
if i <= 1 or line == '\n':
pass
elif i <= len(row_ids):
solution[row_ids[i - 2]] = line.strip().split(' ')
elif i <= len(row_ids) + len(col_ids) + 1:
solution[col_ids[i - 2 - len(row_ids)]] = line.strip().split(' ')
else:
print(i)
print(line)
raise Exception("Argggh!")
finally:
os.remove(tmp_file_name + ".sol")
return solution
def get_linear_coefficients(self, variables):
if self.problem is not None:
num_cols = glp_get_num_cols(self.problem.problem)
ia = intArray(num_cols + 1)
da = doubleArray(num_cols + 1)
nnz = glp_get_mat_row(self.problem.problem, self._index, ia, da)
return {
self.problem._variables[ia[i + 1] - 1]: da[i + 1]
for i in range(nnz)
}
else:
raise Exception(
"Can't get coefficients from solver if constraint is not in a model"
)
def get_linear_coefficients(self, variables):
if self.problem is not None:
self.problem.update()
num_cols = glp_get_num_cols(self.problem.problem)
ia = intArray(num_cols + 1)
da = doubleArray(num_cols + 1)
nnz = glp_get_mat_row(self.problem.problem, self._index, ia, da)
coefs = dict.fromkeys(variables, 0.0)
coefs.update({
self.problem._variables[ia[i + 1] - 1]: da[i + 1]
for i in range(nnz)
if self.problem._variables[ia[i + 1] - 1] in variables})
return coefs
else:
raise Exception("Can't get coefficients from solver if constraint is not in a model")
def _add_constraints(self, constraints, sloppy=False):
super(Model, self)._add_constraints(constraints, sloppy=sloppy)
for constraint in constraints:
constraint._problem = None # This needs to be dones in order to not trigger constraint._get_expression()
glp_add_rows(self.problem, 1)
index = glp_get_num_rows(self.problem)
glp_set_row_name(self.problem, index, str(constraint.name))
num_cols = glp_get_num_cols(self.problem)
index_array = intArray(num_cols + 1)
value_array = doubleArray(num_cols + 1)
num_vars = 0 # constraint.variables is too expensive for large problems
if constraint.expression.is_Atom and constraint.expression.is_Symbol:
var = constraint.expression
index_array[1] = var.index
value_array[1] = 1
num_vars += 1
elif constraint.expression.is_Mul:
args = constraint.expression.args
if len(args) > 2:
raise Exception(
"Term(s) %s from constraint %s is not a proper linear term." % (args, constraint))
coeff = float(args[0])
var = args[1]
index_array[1] = var.index
value_array[1] = coeff
num_vars += 1
else:
for i, term in enumerate(constraint.expression.args):
args = term.args
if args == ():
assert term.is_Symbol
coeff = 1
var = term
elif len(args) == 2:
assert args[0].is_Number
assert args[1].is_Symbol
var = args[1]
coeff = float(args[0])
elif len(args) > 2:
raise Exception(
"Term %s from constraint %s is not a proper linear term." % (term, constraint))
index_array[i + 1] = var.index
value_array[i + 1] = coeff
num_vars += 1
glp_set_mat_row(self.problem, index, num_vars,
index_array, value_array)
constraint._problem = self
self._glpk_set_row_bounds(constraint)
def _get_expression(self):
if self.problem is not None:
col_num = glp_get_num_cols(self.problem.problem)
ia = intArray(col_num + 1)
da = doubleArray(col_num + 1)
nnz = glp_get_mat_row(self.problem.problem, self.index, ia, da)
constraint_variables = [
self.problem._variables[glp_get_col_name(
self.problem.problem, ia[i])] for i in range(1, nnz + 1)
]
expression = sympy.Add._from_args([
sympy.Mul._from_args(
(sympy.RealNumber(da[i]), constraint_variables[i - 1]))
for i in range(1, nnz + 1)
])
self._expression = expression
return self._expression
def set_objective(self, expression):
"""Set objective of problem."""
if isinstance(expression, numbers.Number):
# Allow expressions with no variables as objective,
# represented as a number
expression = Expression(offset=expression)
# Clear previous objective
for i in range(swiglpk.glp_get_num_cols(self._p)):
swiglpk.glp_set_obj_coef(self._p, 1 + i, 0)
for variable, value in expression.values():
var_index = self._variables[variable]
swiglpk.glp_set_obj_coef(self._p, var_index, value)
swiglpk.glp_set_obj_coef(self._p, 0, expression.offset)
def set_objective(self, expression):
"""Set objective of problem."""
if isinstance(expression, numbers.Number):
# Allow expressions with no variables as objective,
# represented as a number
expression = Expression(offset=expression)
# Clear previous objective
for i in range(swiglpk.glp_get_num_cols(self._p)):
swiglpk.glp_set_obj_coef(self._p, 1 + i, 0)
for variable, value in expression.values():
var_index = self._variables[variable]
swiglpk.glp_set_obj_coef(self._p, var_index, value)
swiglpk.glp_set_obj_coef(self._p, 0, expression.offset)
def _set_coefficients_low_level(self, variables_coefficients_dict):
if self.problem is not None:
problem = self.problem.problem
indices_coefficients_dict = dict(
[(variable.index, coefficient) for variable, coefficient in six.iteritems(variables_coefficients_dict)])
num_cols = glp_get_num_cols(problem)
ia = intArray(num_cols + 1)
da = doubleArray(num_cols + 1)
index = self.index
num = glp_get_mat_row(self.problem.problem, index, ia, da)
for i in range(1, num + 1):
try:
da[i] = indices_coefficients_dict[ia[i]]
except KeyError:
pass
glp_set_mat_row(self.problem.problem, index, num, ia, da)
else:
raise Exception(
'_set_coefficients_low_level works only if a constraint is associated with a solver instance.')
def _add_constraints(self, constraints, sloppy=False):
super(Model, self)._add_constraints(constraints, sloppy=sloppy)
for constraint in constraints:
constraint._problem = None # This needs to be done in order to not trigger constraint._get_expression()
glp_add_rows(self.problem, 1)
index = glp_get_num_rows(self.problem)
glp_set_row_name(self.problem, index, str(constraint.name))
num_cols = glp_get_num_cols(self.problem)
index_array = intArray(num_cols + 1)
value_array = doubleArray(num_cols + 1)
num_vars = 0 # constraint.variables is too expensive for large problems
offset, coef_dict, _ = parse_optimization_expression(constraint, linear=True)
num_vars = len(coef_dict)
for i, (var, coef) in enumerate(coef_dict.items()):
index_array[i + 1] = var._index
value_array[i + 1] = float(coef)
glp_set_mat_row(self.problem, index, num_vars,
index_array, value_array)
constraint._problem = self
self._glpk_set_row_bounds(constraint)
def _add_constraints(self, constraints, sloppy=False):
super(Model, self)._add_constraints(constraints, sloppy=sloppy)
for constraint in constraints:
constraint._problem = None # This needs to be done in order to not trigger constraint._get_expression()
glp_add_rows(self.problem, 1)
index = glp_get_num_rows(self.problem)
glp_set_row_name(self.problem, index, str(constraint.name))
num_cols = glp_get_num_cols(self.problem)
index_array = intArray(num_cols + 1)
value_array = doubleArray(num_cols + 1)
num_vars = 0 # constraint.variables is too expensive for large problems
coef_dict, _ = parse_optimization_expression(constraint, linear=True)
num_vars = len(coef_dict)
for i, (var, coef) in enumerate(coef_dict.items()):
index_array[i + 1] = var._index
value_array[i + 1] = float(coef)
glp_set_mat_row(self.problem, index, num_vars,
index_array, value_array)
constraint._problem = self
self._glpk_set_row_bounds(constraint)
def _initialize_model_from_problem(self, problem):
try:
self.problem = problem
glp_create_index(self.problem)
except TypeError:
raise TypeError("Provided problem is not a valid GLPK model.")
row_num = glp_get_num_rows(self.problem)
col_num = glp_get_num_cols(self.problem)
for i in range(1, col_num + 1):
var = Variable(
glp_get_col_name(self.problem, i),
lb=glp_get_col_lb(self.problem, i),
ub=glp_get_col_ub(self.problem, i),
problem=self,
type=_GLPK_VTYPE_TO_VTYPE[
glp_get_col_kind(self.problem, i)]
)
# This avoids adding the variable to the glpk problem
super(Model, self)._add_variables([var])
variables = self.variables
for j in range(1, row_num + 1):
ia = intArray(col_num + 1)
da = doubleArray(col_num + 1)
nnz = glp_get_mat_row(self.problem, j, ia, da)
constraint_variables = [variables[ia[i] - 1] for i in range(1, nnz + 1)]
# Since constraint expressions are lazily retrieved from the solver they don't have to be built here
# lhs = _unevaluated_Add(*[da[i] * constraint_variables[i - 1]
# for i in range(1, nnz + 1)])
lhs = 0
glpk_row_type = glp_get_row_type(self.problem, j)
if glpk_row_type == GLP_FX:
row_lb = glp_get_row_lb(self.problem, j)
row_ub = row_lb
elif glpk_row_type == GLP_LO:
row_lb = glp_get_row_lb(self.problem, j)
row_ub = None
elif glpk_row_type == GLP_UP:
row_lb = None
row_ub = glp_get_row_ub(self.problem, j)
elif glpk_row_type == GLP_DB:
row_lb = glp_get_row_lb(self.problem, j)
row_ub = glp_get_row_ub(self.problem, j)
elif glpk_row_type == GLP_FR:
row_lb = None
row_ub = None
else:
raise Exception(
"Currently, optlang does not support glpk row type %s"
% str(glpk_row_type)
)
log.exception()
if isinstance(lhs, int):
lhs = symbolics.Integer(lhs)
elif isinstance(lhs, float):
lhs = symbolics.Real(lhs)
constraint_id = glp_get_row_name(self.problem, j)
for variable in constraint_variables:
try:
self._variables_to_constraints_mapping[variable.name].add(constraint_id)
except KeyError:
self._variables_to_constraints_mapping[variable.name] = set([constraint_id])
super(Model, self)._add_constraints(
[Constraint(lhs, lb=row_lb, ub=row_ub, name=constraint_id, problem=self, sloppy=True)],
sloppy=True
)
term_generator = (
(glp_get_obj_coef(self.problem, index), variables[index - 1])
for index in range(1, glp_get_num_cols(problem) + 1)
)
self._objective = Objective(
symbolics.add(
[symbolics.mul((symbolics.Real(term[0]), term[1])) for term in term_generator if
term[0] != 0.]
),
problem=self,
direction={GLP_MIN: 'min', GLP_MAX: 'max'}[glp_get_obj_dir(self.problem)])
glp_scale_prob(self.problem, GLP_SF_AUTO)
def term_generator():
for index in range(1, glp_get_num_cols(self.problem.problem) + 1):
coeff = glp_get_obj_coef(self.problem.problem, index)
if coeff != 0.:
yield (symbolics.Real(coeff), variables[index - 1])
def __init__(self, problem=None, *args, **kwargs):
super(Model, self).__init__(*args, **kwargs)
self.configuration = Configuration()
if problem is None:
self.problem = glp_create_prob()
glp_create_index(self.problem)
if self.name is not None:
glp_set_prob_name(self.problem, str(self.name))
else:
try:
self.problem = problem
glp_create_index(self.problem)
except TypeError:
raise TypeError("Provided problem is not a valid GLPK model.")
row_num = glp_get_num_rows(self.problem)
col_num = glp_get_num_cols(self.problem)
for i in range(1, col_num + 1):
var = Variable(
glp_get_col_name(self.problem, i),
lb=glp_get_col_lb(self.problem, i),
ub=glp_get_col_ub(self.problem, i),
problem=self,
type=_GLPK_VTYPE_TO_VTYPE[
glp_get_col_kind(self.problem, i)]
)
# This avoids adding the variable to the glpk problem
super(Model, self)._add_variables([var])
variables = self.variables
for j in range(1, row_num + 1):
ia = intArray(col_num + 1)
da = doubleArray(col_num + 1)
nnz = glp_get_mat_row(self.problem, j, ia, da)
constraint_variables = [variables[ia[i] - 1] for i in range(1, nnz + 1)]
# Since constraint expressions are lazily retrieved from the solver they don't have to be built here
# lhs = _unevaluated_Add(*[da[i] * constraint_variables[i - 1]
# for i in range(1, nnz + 1)])
lhs = 0
glpk_row_type = glp_get_row_type(self.problem, j)
if glpk_row_type == GLP_FX:
row_lb = glp_get_row_lb(self.problem, j)
row_ub = row_lb
elif glpk_row_type == GLP_LO:
row_lb = glp_get_row_lb(self.problem, j)
row_ub = None
elif glpk_row_type == GLP_UP:
row_lb = None
row_ub = glp_get_row_ub(self.problem, j)
elif glpk_row_type == GLP_DB:
row_lb = glp_get_row_lb(self.problem, j)
row_ub = glp_get_row_ub(self.problem, j)
elif glpk_row_type == GLP_FR:
row_lb = None
row_ub = None
else:
raise Exception(
"Currently, optlang does not support glpk row type %s"
% str(glpk_row_type)
)
log.exception()
if isinstance(lhs, int):
lhs = sympy.Integer(lhs)
elif isinstance(lhs, float):
lhs = sympy.RealNumber(lhs)
constraint_id = glp_get_row_name(self.problem, j)
for variable in constraint_variables:
try:
self._variables_to_constraints_mapping[variable.name].add(constraint_id)
except KeyError:
self._variables_to_constraints_mapping[variable.name] = set([constraint_id])
super(Model, self)._add_constraints(
[Constraint(lhs, lb=row_lb, ub=row_ub, name=constraint_id, problem=self, sloppy=True)],
sloppy=True
)
term_generator = (
(glp_get_obj_coef(self.problem, index), variables[index - 1])
for index in range(1, glp_get_num_cols(problem) + 1)
)
self._objective = Objective(
_unevaluated_Add(
*[_unevaluated_Mul(sympy.RealNumber(term[0]), term[1]) for term in term_generator if
term[0] != 0.]),
problem=self,
direction={GLP_MIN: 'min', GLP_MAX: 'max'}[glp_get_obj_dir(self.problem)])
glp_scale_prob(self.problem, GLP_SF_AUTO)
def term_generator():
for index in range(1, glp_get_num_cols(self.problem.problem) + 1):
coeff = glp_get_obj_coef(self.problem.problem, index)
if coeff != 0.:
yield (sympy.RealNumber(coeff), variables[index - 1])
def test_glpk_read_cplex():
problem = glpk_read_cplex(TESTMODELPATH)
nose.tools.assert_equal(glp_get_num_rows(problem), 72)
nose.tools.assert_equal(glp_get_num_cols(problem), 95)
def test_glpk_read_cplex():
problem = glpk_read_cplex(TESTMODELPATH)
nose.tools.assert_equal(glp_get_num_rows(problem), 72)
nose.tools.assert_equal(glp_get_num_cols(problem), 95)
def check_dimensions(glpk_problem, model):
"""
Tests that the glpk problem and the interface model have the same
number of rows (constraints) and columns (variables).
"""
assert glp_get_num_cols(glpk_problem) == len(model.variables)
def check_dimensions(glpk_problem, model):
"""
Tests that the glpk problem and the interface model have the same
number of rows (constraints) and columns (variables).
"""
assert glp_get_num_cols(glpk_problem) == len(model.variables)
def check_dimensions(model, glpk_problem):
nose.tools.assert_true(glp_get_num_cols(glpk_problem) == len(model.variables))
