comb_n: All k possible combinations from n elements

In Rfast: A Collection of Efficient and Extremely Fast R Functions

All k possible combinations from n elements

Description

All k possible combinations from n elements.

Usage

comb_n(n, k,simplify=TRUE)

Arguments

n	A positive INTEGER number or a vector with numbers.
k	A positive integer number at most equal to n or at most equal to the length of n, if n is a vector.
simplify	A logical value for return List instead of matrix.

Value

A matrix with k columns and rows equal to the number of possible unique combinations of n with k elements. If simplify is set to TRUE then a list with k values where each value has length equal to the number of possible unique combinations of n with k elements.

Author(s)

Manos Papadakis and Marios Dimitriadis

R implementation and documentation: Manos Papadakis <[e-mail]> and Marios Dimitriadis <[e-mail]>.

References

Nijenhuis A. and Wilf H.S. (1978). Combinatorial Algorithms for Computers and Calculators. Academic Press, NY.

See Also

nth, colMaxs, colMins, colrange

Examples

comb_n(20, 4)
combn(20, 4)
x <- rnorm(5)
res<-comb_n(x, 3)

Rfast documentation built on Nov. 9, 2023, 5:06 p.m.