laser.measles.biweekly.model

model

A class to represent the biweekly model.

BiweeklyModel(scenario, params, name='biweekly')

Bases: BaseLaserModel

Population-level measles model with 14-day (biweekly) timesteps.

Tracks SEIR compartment counts per patch without individual agents, making it significantly faster than ABMModel for large-scale parameter sweeps and multi-country analyses. Choose this model when individual-level detail is not required and computational speed is a priority. For daily timesteps with explicit SEIR compartment dynamics, see CompartmentalModel.

This is the first object created in the build model stage of the researcher workflow. After construction, attach components with add_component or by setting the components property, then call model.run().

Parameters:

Name	Type	Description	Default
scenario	DataFrame | BaseBiweeklyScenario	Metapopulation patch data. Required columns: id (str), pop (int), lat (Float64), lon (Float64), mcv1 (Float64). A plain polars.DataFrame is automatically wrapped.	required
params	BiweeklyParams	Simulation parameters including num_ticks, seed, and start_time.	required
name	str	Display name for log messages. Defaults to "biweekly".	'biweekly'

Examples:

from laser.measles.biweekly import BiweeklyModel, BiweeklyParams

params = BiweeklyParams(num_ticks=26, seed=42, start_time="2000-01")
model = BiweeklyModel(scenario=df, params=params)
model.components = [InfectionSeedingProcess, InfectionProcess]
model.run()

__call__(model, tick)

Updates the model for the next tick.

Parameters:

Name	Type	Description	Default
model		The model containing the patches and their populations.	required
tick	int	The current time step or tick.	required

Returns:

Type	Description
None	None

infect(indices, num_infected)

Infects the given nodes with the given number of infected individuals.

Parameters:

Name	Type	Description	Default
indices	int | ndarray	The indices of the nodes to infect.	required
num_infected	int | ndarray	The number of infected individuals to infect.	required

recover(indices, num_recovered)

Recovers the given nodes with the given number of recovered individuals. Moves individuals from Infected to Recovered compartment.

Parameters:

Name	Type	Description	Default
indices	int | ndarray	The indices of the nodes to recover.	required
num_recovered	int | ndarray	The number of recovered individuals.	required