Nothing
##' dmeasure specification
##'
##' Specification of the measurement model density function, dmeasure.
##'
##' @name dmeasure_spec
##' @rdname dmeasure_spec
##' @family implementation information
##' @seealso \code{\link{dmeasure}}
##' @details
##' The measurement model is the link between the data and the unobserved state process.
##' It can be specified either by using one or both of the \code{rmeasure} and \code{dmeasure} arguments.
##'
##' Suppose you have a procedure to compute the probability density of an observation given the value of the latent state variables.
##' Then you can furnish \preformatted{
##' dmeasure = f}
##' to \pkg{pomp} algorithms,
##' where \code{f} is a C snippet or \R function that implements your procedure.
##'
##' Using a C snippet is much preferred, due to its much greater computational efficiency.
##' See \code{\link{Csnippet}} for general rules on writing C snippets.
##' The goal of a \dfn{dmeasure} C snippet is to fill the variable \code{lik} with the either the probability density or the log probability density, depending on the value of the variable \code{give_log}.
##'
##' In writing a \code{dmeasure} C snippet, observe that:
##' \enumerate{
##' \item In addition to the states, parameters, covariates (if any), and observables, the variable \code{t}, containing the time of the observation will be defined in the context in which the snippet is executed.
##' \item Moreover, the Boolean variable \code{give_log} will be defined.
##' \item The goal of a dmeasure C snippet is to set the value of the \code{lik} variable to the likelihood of the data given the state, if \code{give_log == 0}.
##' If \code{give_log == 1}, \code{lik} should be set to the log likelihood.
##' }
##'
##' If \code{dmeasure} is to be provided instead as an \R function, this is accomplished by supplying \preformatted{
##' dmeasure = f}
##' to \code{pomp}, where \code{f} is a function.
##' The arguments of \code{f} should be chosen from among the observables, state variables, parameters, covariates, and time.
##' It must also have the arguments \code{\dots}, and \code{log}.
##' It can take additional arguments via the \link[=userdata]{userdata facility}.
##' \code{f} must return a single numeric value, the probability density (or log probability density if \code{log = TRUE}) of \code{y} given \code{x} at time \code{t}.
##'
##' @example examples/dmeasure_spec.R
##'
##' @section Important note:
##' \strong{It is a common error to fail to account for both \code{log = TRUE} and \code{log = FALSE} when writing the \code{dmeasure} C snippet or function.}
##'
##' @section Default behavior:
##' If \code{dmeasure} is left unspecified, calls to \code{\link{dmeasure}} will return missing values (\code{NA}).
##'
##' @inheritSection pomp Note for Windows users
##'
NULL
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.