Source code for yonderdrake.time.formulations

"""Public choices for fractional time formulation."""

from __future__ import annotations

from dataclasses import dataclass




@dataclass(frozen=True, slots=True)
class Recurrence:
    """Eliminated constant-memory recurrence formulation."""

    interpolant: str = "linear"

    def __post_init__(self) -> None:
        if self.interpolant != "linear":
            raise ValueError("only interpolant='linear' is supported")





@dataclass(frozen=True, slots=True)
class AuxiliaryODE:
    """Monolithic physical-plus-mode auxiliary-ODE formulation."""

    scheme: str = "backward_euler"
    coupling: str = "monolithic"

    def __post_init__(self) -> None:
        if self.scheme not in {"backward_euler", "trapezoidal"}:
            raise ValueError(
                "scheme must be 'backward_euler' or 'trapezoidal'"
            )
        if self.coupling != "monolithic":
            raise ValueError("only coupling='monolithic' is supported")