% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/rxsolve.R
\name{rxIsImplicit}
\alias{rxIsImplicit}
\title{Check whether an ODE solving method requires a Jacobian (is implicit)}
\usage{
rxIsImplicit(method)
}
\arguments{
\item{method}{A character vector of method names or an integerish vector of
method codes (as returned by \code{\link[=odeMethodToInt]{odeMethodToInt()}}).  Vectorised.}
}
\value{
A logical vector the same length as \code{method}.  \code{TRUE} if the
corresponding method is implicit and requires a Jacobian.
}
\description{
Implicit ODE solvers linearise the system at each step and therefore
require the Jacobian df/dy.  rxode2 auto-computes a symbolic Jacobian
when one of these methods is requested and falls back to \code{"liblsoda"} if
symbolic differentiation fails.  Use this function to test whether a
method string or integer code corresponds to an implicit solver.
}
\details{
Implicit methods are:
\code{"ros4"} (13), \code{"iem"} (14), \code{"ros43"} (31), \code{"ros6"} (32),
\code{"backwardEuler"} (33), \code{"gauss6"} (34), \code{"iiic6"} (35), \code{"radauiia5"} (36),
\code{"geng5"} (37), \code{"sdirk43"} (38).
}
\examples{
rxIsImplicit("ros4")              # TRUE
rxIsImplicit("liblsoda")          # FALSE
rxIsImplicit(c("ros43", "dop853", "iem"))  # TRUE FALSE TRUE
rxIsImplicit(13L)                 # TRUE  (ros4)
rxIsImplicit(0L)                  # FALSE (dop853)

}
\seealso{
\code{\link[=odeMethodToInt]{odeMethodToInt()}}
}
