R: apply() for big.matrix objects

apply,big.matrix-method {biganalytics} | R Documentation

## apply() for big.matrix objects

### Description

apply for `big.matrix` objects. Note that the performance may be degraded (compared to `apply` with regular R matrices) because of S4 overhead associated with extracting data from `big.matrix` objects. This sort of limitation is unavoidable and would be the case (or even worse) with other "custom" data structures. Of course, this would only be partically significant if you are applying over lengthy rows or columns.

### Usage

    ## S4 method for signature 'big.matrix'
    apply(X, MARGIN, FUN, ...)

### Arguments

`X` | a big.matrix object.
`MARGIN` | the margin. May be may only be 1 or 2, but otherwise conforming to what you would expect from `apply()`.
`FUN` | the function to apply.
`...` | other parameters to pass to the FUN parameter.

### Examples

    library(bigmemory)
    options(bigmemory.typecast.warning=FALSE)
    x <- big.matrix(5, 2, type="integer", init=0,
                    dimnames=list(NULL, c("alpha", "beta")))
    x[,] <- round(rnorm(10))
    biganalytics::apply(x, 1, mean)

[Package biganalytics version 1.1.14 Index]