R: Add the order of a ff vector of the 'ff' vector 'x'

addfforder {ffbase} | R Documentation

## Add the order of a ff vector of the `ff` vector `x`

### Description

Add a ff vector that contains the order of the `ff` vector `x` as an attribute. The order can be retrieved using `ffordered`. Note that you have to assign the result to the original vector `x`.

### Usage

    addfforder(x, addsorted = FALSE, ...)

    ffordered(x)

    ffsorted(x)

### Arguments

`x` | `ff` vector to be indexed
`addsorted` | should the sorted values also be stored in `ffsorted`?
`...` | parameters that will be passed on to `fforder`.

### Value

The updated vector `x`

### Examples

    x <- ff(rnorm(10))

    # adds an index to x (note the assignment)
    x <- addfforder(x)

    # retrieve ffindex
    o <- ffordered(x)

    o
    # use it to sort the original vector
    x[o]

[Package ffbase version 0.13.1 Index]