R: Small cache access methods

is.sorted.integer64 {bit64} | R Documentation

## Small cache access methods

### Description

These methods are packaged here for methods in packages `bit64` and `ff`.

### Usage

    	## S3 method for class 'integer64'
    is.sorted(x, ...)
    	## S3 method for class 'integer64'
    na.count(x, ...)
    	## S3 method for class 'integer64'
    nvalid(x, ...)
    	## S3 method for class 'integer64'
    nunique(x, ...)
    	## S3 method for class 'integer64'
    nties(x, ...)

### Arguments

`x` | some object
`...` | ignored

### Details

All these functions benefit from a `sortcache`, `ordercache` or `sortordercache`. `na.count`, `nvalid` and `nunique` also benefit from a `hashcache`.
`is.sorted` checks for sortedness of `x` (NAs sorted first)
`na.count` returns the number of `NA`s
`nvalid` returns the number of valid data points, usually `length` minus `na.count`.
`nunique` returns the number of unique values
`nties` returns the number of tied values.

### Value

`is.sorted` returns a logical scalar, the other methods return an integer scalar.

### Note

If a `cache` exists but the desired value is not cached, then these functions will store their result in the cache. We do not consider this a relevant side-effect, since these small cache results do not have a relevant memory footprint.

### Author(s)

Jens Oehlschlägel <Jens.Oehlschlaegel@truecluster.com>

### See Also

`cache` for caching functions and `sortordercache` for functions creating big caches

### Examples

    	x <- as.integer64(sample(c(rep(NA, 9), 1:9), 32, TRUE))
     length(x)
     na.count(x)
     nvalid(x)
     nunique(x)
     nties(x)
     table.integer64(x)
     x

[Package bit64 version 4.0.2 Index]