ichimoku (version 1.5.5)

grid_dup: Duplicates of expand.grid for 2 Variables

Description

Create a vector of element positions of duplicates in the output of expand.grid on 2 identical vectors. An efficient method of creating combinations for 2 variables.

Usage

grid_dup(n, omit.id)

Value

A numeric vector.

Arguments

n

the length of vector passed to expand.grid().

omit.id

(optional) set to TRUE to also select the elements where the 2 items are identical. The output of expand.grid, subset to remove duplicates with 'omit.id' set to TRUE would be the equivalent of utils::combn(n, 2).

Examples

n <- 3
expand.grid(1:n, 1:n)
expand.grid(1:n, 1:n)[-grid_dup(n), ]
expand.grid(1:n, 1:n)[-grid_dup(n, omit.id = TRUE), ]