covariate_table: Covariates

In pomp: Statistical Inference for Partially Observed Markov Processes

Covariates

Description

Incorporating time-varying covariates using lookup tables.

Usage

## S4 method for signature 'numeric'
covariate_table(..., order = c("linear", "constant"), times)

## S4 method for signature 'character'
covariate_table(..., order = c("linear", "constant"), times)

Arguments

...	numeric vectors or data frames containing time-varying covariates. It must be possible to bind these into a data frame.
order	the order of interpolation to be used. Options are “linear” (the default) and “constant”. Setting order="linear" treats the covariates as piecewise linear functions of time; order="constant" treats them as right-continuous piecewise constant functions.
times	the times corresponding to the covariates. This may be given as a vector of (non-decreasing, finite) numerical values. Alternatively, one can specify by name which of the given variables is the time variable.

Details

If the ‘pomp’ object contains covariates (specified via the covar argument), then interpolated values of the covariates will be available to each of the model components whenever it is called. In particular, variables with names as they appear in the covar covariate table will be available to any C snippet. When a basic component is defined using an R function, that function will be called with an extra argument, covars, which will be a named numeric vector containing the interpolated values from the covariate table.

An exception to this rule is the prior (rprior and dprior): covariate-dependent priors are not allowed. Nor are parameter transformations permitted to depend upon covariates.

See Also

More on implementing POMP models: Csnippet, accumvars, basic_components, betabinomial, dinit_spec, dmeasure_spec, dprocess_spec, emeasure_spec, eulermultinom, parameter_trans(), pomp-package, pomp_constructor, prior_spec, rinit_spec, rmeasure_spec, rprocess_spec, skeleton_spec, transformations, userdata, vmeasure_spec

More on interpolation: bsplines, lookup()

pomp documentation built on Aug. 8, 2023, 1:08 a.m.