seriation (version 1.2-0)

permutation_vector: Class ser_permutation_vector -- A Single Permutation Vector for Seriation

Description

The class ser_permutation_vector represents a single permutation vector.

Usage

## constructor
ser_permutation_vector(x, method = NULL)

Arguments

x

an object which contains a permutation vector (currently an integer vector or an object of class hclust). The value NA creates an identity permutation.

method

a string representing the method used to obtain the permutation vector

Value

• An object of class ser_permutation_vector.

Details

A permutation vector maps a set of $n$ objects ${O_1, O_2, ..., O_n}$ onto itself. In seriation we represent a permutation $\pi$ as a vector which lists the objects in their permuted order. For example, the permutation vector $\langle3, 1, 2\rangle$ indicates that in first position is the object with index 3 then the object with index 1 and finally the object with index 2. A permutation vector can be extracted from a permuation vector object via get_order(). Such a permutation vector can be directly used to subset the list of original objects with "[" to apply the permutation. Note: An alternative way to specify a permutation is via a list of the ranks of the objects after permutation (see get_rank()).

ser_permutation_vector objects are usually packed into a ser_permutation object which is a collection of $k$ permutation vectors for $k$-mode data.

The constructor ser_permutation_vector checks if the permutation vector is valid (i.e. if all integers occur exactly once).

The following functions are implemented: print, rev, length, get_order, get_rank, get_method.

See Also

ser_permutation, get_order, get_rank, get_permutation_matrix, permutation_vector2matrix.

Examples

p <- ser_permutation_vector(sample(10), "random")
p

## some methods
length(p)
get_method(p)
get_order(p)
get_rank(p)
get_permutation_matrix(p)

r <- rev(p)
r
get_order(r)

## create a indentity permutation vector (with unknown length)
ip <- ser_permutation_vector(NA)
ip