Macro sde 

sde!() { /* proc-macro */ }

Define an SDE (stochastic differential equation) model.

Builds a particle‑based stochastic model with a drift term, a diffusion term, and a configurable number of particles. The macro generates an SDE value with full metadata.

Fields

Field	Required	Description
name	yes	Model name
params	yes	Parameter identifiers
covariates	no	Covariate identifiers
states	yes	State identifiers
outputs	yes	Output identifiers
particles	yes	Number of particles for the simulation
routes	no	Route declarations
drift	yes	Closure |x, p, t, dx, cov| { … } for the deterministic drift
diffusion	yes	Closure |p, sigma| { … } setting per‑state diffusion coefficients
lag	no	Lag‑time closure
fa	no	Bioavailability closure
init	no	Initial‑state closure
out	yes	Output mapping closure

Example

let model = sde! {
    name: "one_cmt_sde",
    params: [ke, sigma_ke, v],
    states: [central],
    outputs: [cp],
    particles: 16,
    routes: [infusion(iv) -> central],
    drift: |x, _p, _t, dx, _cov| {
        dx[central] = -ke * x[central];
    },
    diffusion: |_p, sigma| {
        sigma[central] = sigma_ke;
    },
    out: |x, _p, _t, _cov, y| {
        y[cp] = x[central] / v;
    },
};