Constructs an object of class sde_ssm
by defining the functions for
the drift, diffusion and derivative of diffusion terms of univariate SDE,
as well as the log-density of observation equation. We assume that the
observations are measured at integer times (missing values are allowed).
sde_ssm(y, drift, diffusion, ddiffusion, obs_pdf, prior_pdf, theta, x0,
positive)
Observations as univariate time series (or vector) of length \(n\).
An external pointers for the C++ functions which define the drift, diffusion and derivative of diffusion functions of SDE.
An external pointer for the C++ function which computes the observational log-density given the the states and parameter vector theta.
An external pointer for the C++ function which computes the prior log-density given the parameter vector theta.
Parameter vector passed to all model functions.
Fixed initial value for SDE at time 0.
If TRUE
, positivity constraint is
forced by abs
in Millstein scheme.
Object of class sde_ssm
.
As in case of nlg_ssm
models, these general models need a bit more effort from
the user, as you must provide the several small C++ snippets which define the
model structure. See SDE vignette for an example.