def _linear_constraint(
cls, var_names: Dict[Var, str], constraint: LinearConstraint
) -> Tuple[Dict[str, float], str, float]:
left_expr = constraint.get_left_expr()
right_expr = constraint.get_right_expr()
# for linear constraints we may get an instance of Var instead of expression,
# e.g. x + y = z
if not isinstance(left_expr, (AbstractLinearExpr, Var)):
raise QiskitOptimizationError(
f"Unsupported expression: {left_expr} {type(left_expr)}")
if not isinstance(right_expr, (AbstractLinearExpr, Var)):
raise QiskitOptimizationError(
f"Unsupported expression: {right_expr} {type(right_expr)}")
if isinstance(left_expr, Var):
left_expr = left_expr + 0
if isinstance(right_expr, Var):
right_expr = right_expr + 0
linear = {}
for x in left_expr.iter_variables():
linear[var_names[x]] = left_expr.get_coef(x)
for x in right_expr.iter_variables():
linear[var_names[x]] = linear.get(var_names[x],
0.0) - right_expr.get_coef(x)
rhs = right_expr.constant - left_expr.constant
if constraint.sense not in cls._sense_dict:
raise QiskitOptimizationError(
f"Unsupported constraint sense: {constraint}")
return linear, cls._sense_dict[constraint.sense], rhs
def _linear_constraint(
self, constraint: LinearConstraint
) -> Tuple[Dict[str, float], str, float]:
left_expr = constraint.get_left_expr()
right_expr = constraint.get_right_expr()
# for linear constraints we may get an instance of Var instead of expression,
# e.g. x + y = z
if not isinstance(left_expr, (Expr, Var)):
raise QiskitOptimizationError(
f"Unsupported expression: {left_expr} {type(left_expr)}")
if not isinstance(right_expr, (Expr, Var)):
raise QiskitOptimizationError(
f"Unsupported expression: {right_expr} {type(right_expr)}")
if constraint.sense not in self._sense_dict:
raise QiskitOptimizationError(
f"Unsupported constraint sense: {constraint}")
if isinstance(left_expr, Var):
left_expr = left_expr + 0 # Var + 0 -> LinearExpr
left_linear = self._linear_expr(left_expr)
if isinstance(right_expr, Var):
right_expr = right_expr + 0
right_linear = self._linear_expr(right_expr)
linear = self._subtract(left_linear, right_linear)
rhs = right_expr.constant - left_expr.constant
return linear, self._sense_dict[constraint.sense], rhs