length.hi: Hybrid Index, querying

In kindlychung/ff: memory-efficient storage of large data on disk and fast access functions

Description

Functions to query some index attributes

Usage

## S3 method for class 'hi'
length(x)
maxindex(x, ...)
poslength(x, ...)
## S3 method for class 'hi'
maxindex(x, ...)
## S3 method for class 'ri'
maxindex(x, ...)
## S3 method for class 'bit'
maxindex(x, ...)
## S3 method for class 'bitwhich'
maxindex(x, ...)
## S3 method for class 'logical'
maxindex(x, ...)
## Default S3 method:
maxindex(x, ...)
## S3 method for class 'hi'
poslength(x, ...)
## S3 method for class 'ri'
poslength(x, ...)
## S3 method for class 'bit'
poslength(x, ...)
## S3 method for class 'bitwhich'
poslength(x, ...)
## S3 method for class 'logical'
poslength(x, ...)
## Default S3 method:
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 the generic poslength returns the number of selected elements (which for negative indices is maxindex(x) - length(unique(x))). The generic maxindex returns the highest possible index position.

Value

an integer scalar

Note

duplicated negative indices are removed

Author(s)

Jens Oehlschl<c3><a4>gel

See Also

hi, as.hi, length.ff, length

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))

kindlychung/ff documentation built on May 20, 2019, 9:58 a.m.