==================== The weaver Package ==================== Tools and extensions for processing Sweave documents ---------------------------------------------------- Authors: Seth Falcon and Robert Gentleman Abstract ======== The weaver package provides extensions to the Sweave utilities included in R's utils package. The focus of the extensions is on caching computationally expensive (time consuming) code chunks in Sweave documents. The weaver package uses Luke Tierney's codetools package and Dirk Eddelbuettel's digest package to provide a caching mechanism that tracks dependencies among the R code expressions in the document. This allows weaver to decide when the results of a computation can be retrieved from the cache and when they must be recomputed. In this paper we demonstrate the use of weaver and discuss its implementation.