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 booltypes. The generic poslength gives the number of positively selected elements, i.e. sum(logical) for all booltypes (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 Sept. 20, 2024, 5:08 p.m.