diff options
| -rw-r--r-- | sumofsquares/problems.py | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/sumofsquares/problems.py b/sumofsquares/problems.py index d884899..4256642 100644 --- a/sumofsquares/problems.py +++ b/sumofsquares/problems.py @@ -108,6 +108,7 @@ class ConicProblem(Problem): @dataclassabc(frozen=True) class ConicResult(Result): + """ Result of a Conic Problem """ values: dict[OptVariable, float] solver_info: Any @@ -194,11 +195,21 @@ class SOSProblem(Problem): polynomial_variables, variables = partition(is_optvariable, state.indices.keys()) polynomial_variables = tuple(polynomial_variables) # because it is a generator - x = poly.v_stack(polynomial_variables) + x = poly.v_stack((1,) + polynomial_variables) for i, c in enumerate(self.constraints): if isinstance(c, EqualToZero): - state, pm = c.expression.apply(state) - constraints.append(replace(c, expression=pm)) + state, deg = c.expression.degree().apply(state) + + # Polynomial equality must be converted into coefficient + # matching condition + if deg.scalar().constant() > 1: + state, pm = c.expression.linear_in(x).apply(state) + constraints.append(replace(c, expression=pm)) + + # A normal (linear) equality + else: + state, pm = c.expression.apply(state) + constraints.append(replace(c, expression=pm)) elif isinstance(c, NonNegative): if c.domain: @@ -257,6 +268,11 @@ class InternalSOSProblem(Problem): state: ExpressionState def to_conic_problem(self) -> ConicProblem: + """ + Conver the SOS problem into a Conic program. + + TODO: docstring + """ cost = poly.to_affine(self.cost) if cost.degree > 2: raise ValueError("This package can solve at most quadratic conic programs, " @@ -265,6 +281,7 @@ class InternalSOSProblem(Problem): is_qp = (cost.degree == 2) # Sizes + # See docstring of ConicProblem.constraints dims: dict[str, list[int]] = { "z": [], "l": [], "b": [], "q": [], "s": [], "ep": [], "ep*": [], "p": [], "p*": [], |