R: Sorting: convenience wrappers for data.frames

ffdfsort {ff} | R Documentation

## Sorting: convenience wrappers for data.frames

### Description

These functions allow convenient sorting and ordering of collections of (ff) vectors organized in (ffdf) data.frames

### Usage

    dforder(x, ...)
    dfsort(x, ...)
    ramdforder(x, ...)
    ramdfsort(x, ...)
    ffdforder(x, ...)
    ffdfsort(x, ...)

### Arguments

`x` | a `data.frame` (for `dforder, dfsort, ramorder, ramsort`) or an `ffdf` object (for `ffdforder, ffdfsort`)
`...` | further arguments passed to `sort`, `ramsort` or `ffsort` (for objects with one column) or passed to `order`, `ramorder` or `fforder` (for objects with mulitple columns)

### Value

the order functions return an (ff) vector of integer order positions, the sort functions return a sorted clone of the (ffdf) input data.frame

### Author(s)

Jens Oehlschlägel

### See Also

`sort`, `ramsort` or `ffsort`
`order`, `ramorder` or `fforder`

### Examples

       x <- ff(sample(1e5, 1e6, TRUE))
       y <- ff(sample(1e5, 1e6, TRUE))
       z <- ff(sample(1e5, 1e6, TRUE))
       d <- ffdf(x, y, z)
       d2 <- ffdfsort(d)
       d2
       d
       d2 <- d[1:2]
       i <- ffdforder(d2)
       d[i,]
       rm(x, y, z, i, d, d2)
       gc()

[Package ff version 2.2-13 Index]