ult: Extract or replace the *ult*imate (last) element of a vector...

In rpm: Modeling of Revealed Preferences Matchings

Extract or replace the *ult*imate (last) element of a vector or a list, or an element counting from the end.

Description

Extract or replace the *ult*imate (last) element of a vector or a list, or an element counting from the end.

Usage

ult(x, i = 1L) <- value

ult(x, i = 1L)

Arguments

x	a vector or a list.
i	index from the end of the list to extract or replace (where 1 is the last element, 2 is the penultimate element, etc.).
value	Replacement value for the 'i'th element from the end.

Value

An element of 'x'.

Note

Due to the way in which assigning to a function is implemented in R, 'ult(x) <- e' may be less efficient than 'x[[length(x)]] <- e'.

Examples

(x <- c(1:5))
(ult(x) <- 6)
(ult(x, 2) <- 7) # 2nd last.
x



x <- 1:5
(last <- ult(x))
(penultimate <- ult(x, 2)) # 2nd last.

rpm documentation built on May 29, 2024, 12:07 p.m.