HydPy-Test-Stiff-0D (test model for stiff ODEs and scalar sequences)

test_stiff0d is a simple test model that serves to test numerical integration strategies. It can be seen from two perspectives. On the one hand, it implements the Dahlquist test equation (on the real axis only), which is related to stiff initial value problems. On the other hand, it describes a simple storage with a linear loss term and without any input. The loss rate Q and the initial storage content S can be set as required.

class hydpy.models.test_stiff0d.Model[source]

Bases: ELSModel

HydPy-Test-Stiff-0D (test model for stiff ODEs and scalar sequences).

The following methods define the relevant components of a system of ODE equations (e.g. direct runoff):

  • Calc_Q_V1 Calculate the actual storage loss.

The following methods define the complete equations of an ODE system (e.g. change in storage of fast water due to effective precipitation and direct runoff):

  • Calc_S_V1 Calculate the actual storage content.

DOCNAME: DocName = ('Test-Stiff-0D', 'test model for stiff ODEs and scalar sequences')
REUSABLE_METHODS: ClassVar[tuple[type[ReusableMethod], ...]] = ()
class hydpy.models.test_stiff0d.ControlParameters(master: Parameters, cls_fastaccess: type[FastAccessParameter] | None = None, cymodel: CyModelProtocol | None = None)

Bases: SubParameters

Control parameters of model test_stiff0d.

The following classes are selected:

  • K() Storage coefficient [1/T].

class hydpy.models.test_stiff0d.FluxSequences(master: Sequences, cls_fastaccess: type[TypeFastAccess_co] | None = None, cymodel: CyModelProtocol | None = None)

Bases: FluxSequences

Flux sequences of model test_stiff0d.

The following classes are selected:

  • Q() Storage loss [mm/T]

class hydpy.models.test_stiff0d.SolverParameters(master: Parameters, cls_fastaccess: type[FastAccessParameter] | None = None, cymodel: CyModelProtocol | None = None)

Bases: SubParameters

Solver parameters of model test_stiff0d.

The following classes are selected:

  • AbsErrorMax() Absolute numerical error tolerance [mm/T].

  • RelErrorMax() Relative numerical error tolerance [1/T].

  • RelDTMin() Smallest relative integration time step size allowed [-].

  • RelDTMax() Largest relative integration time step size allowed [-].

class hydpy.models.test_stiff0d.StateSequences(master: Sequences, cls_fastaccess: type[TypeFastAccess_co] | None = None, cymodel: CyModelProtocol | None = None)

Bases: StateSequences

State sequences of model test_stiff0d.

The following classes are selected:

  • S() Storage content [mm].