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laser.cohorts.SI

SI

SI model component preset.

Assembles the Susceptible and Infectious compartments with SI-style direct transmission (S → I, no recovery) for use as a standalone SI model.

Infectious

Infectious(model, validating=False)

Infectious (I) compartment component.

Tracks the infectious population and applies non-disease mortality each time step. Initial I counts are read from the scenario at setup.

Initialize the Infectious component.

Parameters:

Name Type Description Default
model Model

The parent model instance.

required
validating bool

Enable validation checks during simulation.

False

properties property

properties

Return node properties required by this component.

Returns:

Type Description
list[PropertyType]

list[PropertyType]: Empty list; mortality tracking belongs to NonDiseaseMortality.

states property

states

Return the compartment state names managed by this component.

Returns:

Type Description
list[str]

list[str]: ["I"]

end_step

end_step(tick)

No-op end-of-step hook for the I compartment.

Parameters:

Name Type Description Default
tick int

Current simulation tick (0-indexed).

required

setup

setup()

Initialize state I at tick 0 from the scenario I column.

start_step

start_step(tick)

No-op start-of-step hook; carry-forward is handled by the Model.

Parameters:

Name Type Description Default
tick int

Current simulation tick (0-indexed).

required

step

step(tick)

No-op step hook for the I compartment.

Parameters:

Name Type Description Default
tick int

Current simulation tick (0-indexed).

required

Susceptible

Susceptible(model, validating=False)

Susceptible (S) compartment component.

Tracks the susceptible population and applies non-disease mortality each time step. Initial S counts are read from the scenario at setup.

Initialize the Susceptible component.

Parameters:

Name Type Description Default
model Model

The parent model instance.

required
validating bool

Enable validation checks during simulation.

False

properties property

properties

Return node properties required by this component.

Returns:

Type Description
list[PropertyType]

list[PropertyType]: Empty list; mortality tracking belongs to NonDiseaseMortality.

states property

states

Return the compartment state names managed by this component.

Returns:

Type Description
list[str]

list[str]: ["S"]

end_step

end_step(tick)

No-op end-of-step hook for the S compartment.

Parameters:

Name Type Description Default
tick int

Current simulation tick (0-indexed).

required

setup

setup()

Initialize state S at tick 0 from the scenario S column.

start_step

start_step(tick)

No-op start-of-step hook; carry-forward is handled by the Model.

Parameters:

Name Type Description Default
tick int

Current simulation tick (0-indexed).

required

step

step(tick)

No-op step hook for the S compartment.

Parameters:

Name Type Description Default
tick int

Current simulation tick (0-indexed).

required

Transmission

Transmission(
    model, beta, seasonality=None, validating=False
)

Bases: TransmissionCommon

Transmission component that moves individuals directly from S to I.

Specialises TransmissionCommon for models without an exposed period (SI, SIR, SIS, SIRS). Newly infected individuals enter the I compartment immediately.

Initialize the S → I transmission component.

Parameters:

Name Type Description Default
model Model

The parent model instance.

required
beta ValuesMap

Per-tick, per-node transmission rate.

required
validating bool

Enable validation checks during simulation.

False

properties property

properties

Return node properties required by this component.

Returns:

Type Description
list[PropertyType]

list[PropertyType]: Parent properties plus ("newly_infectious", nticks, np.int32, 0).

states property

states

Return the compartment state names managed by this component.

Returns:

Type Description
list[str]

list[str]: Parent states plus ["I"].