maxindex: Get maxindex (length of boolean vector) and poslength (number...

In bit: Classes and Methods for Fast Memory-Efficient Boolean Selections

Get maxindex (length of boolean vector) and poslength (number of 'selected' elements)

Description

For is.booltype() objects the term length() is ambiguous. For example the length of which() corresponds to the sum of logical(). The generic maxindex gives length(logical) for all booltype()s. The generic poslength gives the number of positively selected elements, i.e. sum(logical) for all booltype()s (and gives NA if NAs are present).

Usage

## Default S3 method:
maxindex(x, ...)

## Default S3 method:
poslength(x, ...)

## S3 method for class 'logical'
maxindex(x, ...)

## S3 method for class 'logical'
poslength(x, ...)

## S3 method for class 'bit'
maxindex(x, ...)

## S3 method for class 'bit'
poslength(x, ...)

## S3 method for class 'bitwhich'
maxindex(x, ...)

## S3 method for class 'bitwhich'
poslength(x, ...)

## S3 method for class 'which'
maxindex(x, ...)

## S3 method for class 'which'
poslength(x, ...)

## S3 method for class 'ri'
maxindex(x, ...)

## S3 method for class 'ri'
poslength(x, ...)

maxindex(x, ...)

poslength(x, ...)

Arguments

x	an R object, typically a is.booltype() object.
...	further arguments (ignored)

Value

an integer scalar

Methods (by class)

• maxindex(default): default method for maxindex

• maxindex(logical): maxindex method for class logical()

• maxindex(bit): maxindex method for class bit()

• maxindex(bitwhich): maxindex method for class bitwhich()

• maxindex(which): maxindex method for class which()

• maxindex(ri): maxindex method for class ri()

Functions

• poslength(default): default method for poslength

• poslength(logical): poslength method for class logical()

• poslength(bit): poslength method for class bit()

• poslength(bitwhich): poslength method for class bitwhich()

• poslength(which): poslength method for class which()

• poslength(ri): poslength method for class ri()

Examples

r <- ri(1, 2, 12)
i <- as.which(r)
w <- as.bitwhich(r)
b <- as.bit(r)
l <- as.logical(r)
u <- which(l)      # unclassed which

sapply(list(r=r, u=u, i=i, w=w, b=b, l=l), function(x) {
  c(length=length(x), sum=sum(x), maxindex=maxindex(x), poslength=poslength(x))
})

bit documentation built on April 4, 2025, 3:09 a.m.