search for: ffapply

...shFUN=md5)) system.time(id.matrix(x, hashFUN=list)) } # BTW, the following are methods for the upcoming package/class 'ff' # they limit the chunk size of RAM needed for reading the data from disk # yet they assume that the result fits into RAM (and is returned as such) # they rely on ffapply which helps with chunked indexing hash.ff <- function (x, MARGIN = NULL, hashFUN=md5 , return.ff = FALSE , ... # passed to ffapply ) { if (!is.logical(return.ff) || return.ff) .NotYetUsed("return.ff = TRUE") d <- dim(x) if (is.null(MARGIN)) MARGIN <-...

I understand R is a "Pass-By-Value" language. I have a few practical questions, however. I'm dealing with a "large" dataset (~1GB) and so my understanding of the nuances of memory usage in R is becoming important. In an example such as: > d <- read.csv("file.csv"); > n <- apply(d, 1, sum); must "d" be copied to another location in memory in

...t on binary flat files i.e. logicals take up exactly 2 bits to represent TRUE, FALSE and NA. Beyond basic access functions, the ff package also provides compatibility functions that facilitate writing code for ff and ram objects and support for batch processing on ff objects (e.g. as.ram, as.ff, ffapply). A package that supports convenient processing of large ff objects is in the making. R.ff will make the bigger part of R's basic functions available for ff objects through method dispatch and/or an evaluator that handles expressions which contain ff objects. NOTE: A professional extensio...

...t on binary flat files i.e. logicals take up exactly 2 bits to represent TRUE, FALSE and NA. Beyond basic access functions, the ff package also provides compatibility functions that facilitate writing code for ff and ram objects and support for batch processing on ff objects (e.g. as.ram, as.ff, ffapply). A package that supports convenient processing of large ff objects is in the making. R.ff will make the bigger part of R's basic functions available for ff objects through method dispatch and/or an evaluator that handles expressions which contain ff objects. NOTE: A professional extensio...