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\name{DelayedSubassign-class}
\alias{class:DelayedSubassign}
\alias{DelayedSubassign-class}
\alias{DelayedSubassign}
\alias{is_noop,DelayedSubassign-method}
\alias{summary.DelayedSubassign}
\alias{summary,DelayedSubassign-method}
\alias{extract_array,DelayedSubassign-method}
\alias{is_sparse,DelayedSubassign-method}
\alias{extract_sparse_array,DelayedSubassign-method}
\title{DelayedSubassign objects}
\description{
NOTE: This man page is about \link{DelayedArray} internals and is provided
for developers and advanced users only.
The DelayedSubassign class provides a formal representation of a
\emph{delayed multi-dimensional single bracket subassignment}. It is
a concrete subclass of the \link{DelayedUnaryIsoOp} virtual class, which
itself is a subclass of the \link{DelayedUnaryOp} virtual class, which
itself is a subclass of the \link{DelayedOp} virtual class:
\preformatted{
DelayedOp
^
|
DelayedUnaryOp
^
|
DelayedUnaryIsoOp
^
|
DelayedSubassign
}
DelayedSubassign objects are used inside a \link{DelayedArray}
object to represent the \emph{delayed multi-dimensional single bracket
subassignments} carried by the object. They're never exposed to the end
user and are not intended to be manipulated directly.
}
\usage{
\S4method{is_noop}{DelayedSubassign}(x)
\S4method{summary}{DelayedSubassign}(object, ...)
## ~ ~ ~ Seed contract ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
## DelayedSubassign objects inherit the default dim()
## and dimnames() methods defined for DelayedUnaryIsoOp
## derivatives, but overwite their extract_array() method.
\S4method{extract_array}{DelayedSubassign}(x, index)
## ~ ~ ~ Propagation of sparsity ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
\S4method{is_sparse}{DelayedSubassign}(x)
\S4method{extract_sparse_array}{DelayedSubassign}(x, index)
}
\arguments{
\item{x, object}{
A DelayedSubassign object.
}
\item{index}{
See \code{?\link{extract_array}} for a description of the \code{index}
argument.
}
\item{...}{
Not used.
}
}
\seealso{
\itemize{
\item \link{DelayedOp} objects.
\item \code{\link{showtree}} to visualize the nodes and access the
leaves in the tree of delayed operations carried by a
\link{DelayedArray} object.
\item \code{\link{extract_array}} and \code{\link{extract_sparse_array}}.
}
}
\examples{
## DelayedSubassign extends DelayedUnaryIsoOp, which extends
## DelayedUnaryOp, which extends DelayedOp:
extends("DelayedSubassign")
## ---------------------------------------------------------------------
## BASIC EXAMPLE
## ---------------------------------------------------------------------
m0 <- matrix(1:30, ncol=5)
M2 <- M1 <- M0 <- DelayedArray(m0)
showtree(M0)
M1[2:5, 5:4] <- 100
showtree(M1)
class(M1@seed) # a DelayedSubassign object
M2[2:5, 5:4] <- matrix(101:108, ncol=2)
showtree(M2)
class(M2@seed) # a DelayedSubassign object
## ---------------------------------------------------------------------
## PROPAGATION OF SPARSITY
## ---------------------------------------------------------------------
## DelayedSubassign objects don't propagate sparsity at the moment, that
## is, is_sparse() always returns FALSE on them.
## ---------------------------------------------------------------------
## SANITY CHECKS
## ---------------------------------------------------------------------
stopifnot(class(M1@seed) == "DelayedSubassign")
stopifnot(class(M2@seed) == "DelayedSubassign")
}
\keyword{methods}
|
