Initialise the permutation object

This function initialises the permutation object. It must be called before nextPerm can be called

initMC(x)

Arguments

x

a vector of integers, reals, logicals or characters, with at least two elements and no missing values

Value

a object of class mc which is a list containing elements

mode

- the mode of the original data in x, "integer", "double", or mode(x)

set

- a multiset of integer codes 1, ..., k, one code for each unique element of x

elements

- the unique elements of x, so that elements[set] recovers the multiset being permuted

length

- the length of the multiset

plain

- TRUE if elements is a plain integer, double, logical or character vector, which the C++ code can write directly

mc

- an external pointer to the internal C++ object that holds the position of nextPerm. Users should not use this unless they really know what they are doing. It does not survive saving and reloading the object, so call initMC again in a new session

See also

nextPerm

Author

James M. Curran

Examples

x = c(1,1,2,2)
m1 = initMC(x)
m1
#> $mode
#> [1] "integer"
#> 
#> $set
#> [1] 1 1 2 2
#> 
#> $elements
#> [1] 1 2
#> 
#> $length
#> [1] 4
#> 
#> $plain
#> [1] TRUE
#> 
#> $mc
#> <pointer: 0x55a1bbb46990>
#> 
#> attr(,"class")
#> [1] "mc"

## a non-integer example

x = rep(letters[1:4],c(2,1,2,2))
m2 = initMC(x)
m2
#> $mode
#> [1] "character"
#> 
#> $set
#> [1] 1 1 2 3 3 4 4
#> 
#> $elements
#> [1] "a" "b" "c" "d"
#> 
#> $length
#> [1] 7
#> 
#> $plain
#> [1] TRUE
#> 
#> $mc
#> <pointer: 0x55a1bbade3c0>
#> 
#> attr(,"class")
#> [1] "mc"

## a real-valued example

m3 = initMC(c(1.5, 1.5, 2.5))
allPerm(m3)
#>      [,1] [,2] [,3]
#> [1,]  2.5  1.5  1.5
#> [2,]  1.5  2.5  1.5
#> [3,]  1.5  1.5  2.5