length.hi: Hybrid Index, querying

In ff: Memory-Efficient Storage of Large Data on Disk and Fast Access Functions

Hybrid Index, querying

Description

Functions to query some index attributes

Usage

## S3 method for class 'hi'
length(x)
## S3 method for class 'hi'
maxindex(x, ...)
## S3 method for class 'hi'
poslength(x, ...)

Arguments

x	an object of class hi
...	further arguments (not used)

Details

length.hi returns the number of the subsript elements in the index (even if they are negative). By contrast poslength returns the number of selected elements (which for negative indices is maxindex(x) - length(unique(x))). maxindex returns the highest possible index position.

Value

an integer scalar

Note

duplicated negative indices are removed

Author(s)

Jens Oehlschlägel

See Also

hi, as.hi, length.ff, length, poslength, maxindex

Examples

  length(as.hi(-1, maxindex=12))
  poslength(as.hi(-1, maxindex=12))
  maxindex(as.hi(-1, maxindex=12))
  message("note that")
  length(as.hi(c(-1, -1), maxindex=12))
  length(as.hi(c(1,1), maxindex=12))

ff documentation built on Sept. 30, 2024, 9:38 a.m.