laser.measles.mixing.stouffer

`stouffer`

`StoufferMixing(scenario=None, params=None)`

Bases: BaseMixing

Stouffer intervening-opportunities migration model.

Long-distance travel is suppressed by the cumulative population of patches between origin and destination (intervening opportunities):

\[M_{i,j} = k \, p_i^{a} \sum_j \left(\frac{p_j}{\sum_{k \in \Omega(i,j)} p_k}\right)^{b}\]

Parameters:

Name	Type	Description	Default
`scenario`	`DataFrame \| None`	Patch data. `None` when the model will set it automatically.	`None`
`params`	`StoufferParams \| None`	Model parameters. Uses `StoufferParams` defaults if `None`.	`None`

Examples:

from laser.measles.mixing.stouffer import StoufferMixing, StoufferParams
from laser.measles.compartmental import components
from laser.measles import create_component

mixer = StoufferMixing(params=StoufferParams(k=0.01))
infection_params = components.InfectionParams(beta=0.8, mixer=mixer)
model.add_component(create_component(components.InfectionProcess, infection_params))

The include_home model parameter is configured via StoufferParams.

`get_migration_matrix()`

Compute the Stouffer migration matrix.

Returns:

Type	Description
`ndarray`	Migration matrix of shape `(N, N)`.

`StoufferParams`

Bases: BaseModel

Parameters for the Stouffer migration model.

Attributes:

Name	Type	Description
`include_home`	`bool`	Whether to include home in the migration matrix
`k`	`float`	Scale parameter (avg trip probability)

Examples:

from laser.measles.mixing.stouffer import StoufferParams

params = StoufferParams(k=0.02, include_home=True, a=1.0, b=1.0)