pypomp.models.dhaka

pypomp.models.dhaka(dt: float | None = 0.004166666666666667, nstep: int | None = None, gamma: bool = False) Pomp[source]

Creates a POMP model for the Dhaka cholera data.

This function constructs a Partially Observed Markov Process (POMP) model for the Dhaka cholera dataset. The model includes a stochastic process for the underlying disease dynamics and a measurement model for observed deaths.

Parameters:
  • dt (float, optional) – Time step size for the process model. Determines the number of sub-steps per observation interval for the process model.

  • nstep (int, optional) – Number of sub-steps per observation interval for the process model. If None, uses Euler discretization with the specified step size. nstep and dt cannot both be not None.

  • gamma (bool, optional) – Indicator for whether gamma white noise should be used in place of Gaussian noise. This corresponds to a large-population approximation of an overdispersed death process.

Model Parameters

gammafloat

Recovery rate (duration of infectiousness).

epsilonfloat

Rate of waning of immunity for severe infections.

rhofloat

Rate of waning of immunity for inapparent infections.

mfloat

Cholera-specific mortality rate.

cfloat

Fraction of infections that lead to severe (clinically apparent) infection.

beta_trendfloat

Slope of the secular trend in transmission.

bs1-bs6float

Seasonal transmission rates (B-spline coefficients).

sigmafloat

Environmental noise intensity.

taufloat

Measurement error standard deviation.

alphafloat

Non-linear transmission parameter.

deltafloat

Natural mortality rate.

S_0, I_0, Y_0, R1_0, R2_0, R3_0float

Initial value parameters (IVPs) for the model state proportions.

omegas1-omegas6float

Seasonal environmental reservoir parameters (B-spline coefficients for the log-reservoir).

Returns:

A POMP model object representing the Dhaka cholera model.

Return type:

Pomp