R: Chunk bit vectors

chunk.bit {ff} | R Documentation

## Chunk bit vectors

### Description

chunking method for ffdf objects automatically considering RAM requirements from recordsize as calculated from `sum(.rambytes[vmode])`

### Usage

    ## S3 method for class 'bit'
    chunk(x, RECORDBYTES = .rambytes["logical"], BATCHBYTES = getOption("ffbatchbytes"), ...)

### Arguments

`x` | `bit`
`RECORDBYTES` | optional integer scalar representing the bytes needed to process a single element of the bit vector
`BATCHBYTES` | integer scalar limiting the number of bytes to be processed in one chunk, default from `getOption("ffbatchbytes")`, see also `.rambytes`
`...` | further arguments passed to `chunk`

### Value

A list with `ri` indexes each representing one chunk

### Author(s)

Jens Oehlschlägel

### See Also

`chunk`, `bit`

### Examples

      n <- 1000
      x <- bit(n)
      ceiling(n / (300 %/% sum(.rambytes["logical"])))
      chunk(x, BATCHBYTES=300)
      ceiling((n/2) / (100 %/% sum(.rambytes["logical"])))
      chunk(x, from=1, to = n/2, BATCHBYTES=100)
      rm(x, n)

[Package ff version 2.2-13 Index]