ATSP {TSP}

Class ATSP – Asymmetric traveling salesperson problem

Description

Constructor to create an instance of the asymmetric traveling salesperson problem (ATSP) and some auxiliary methods.

Usage

ATSP(x, labels = NULL, method = NULL)

as.ATSP(x)

## S3 method for class 'matrix'
as.ATSP(x)

## S3 method for class 'dist'
as.ATSP(x)

## S3 method for class 'ATSP'
print(x, ...)

## S3 method for class 'ATSP'
n_of_cities(x)

## S3 method for class 'ATSP'
labels(object, ...)

## S3 method for class 'ATSP'
image(x, order, col = gray.colors(64), ...)

## S3 method for class 'ATSP'
as.matrix(x, ...)

Arguments

x, object

an object (a square matrix) to be converted into an ATSP or, for the methods, an object of class ATSP.

labels

optional city labels. If not given, labels are taken from x.

method

optional name of the distance metric.

...

further arguments are passed on.

order

order of cities as an integer vector or an object of class TOUR.

col

color scheme for image.

Details

Objects of class ATSP are internally represented by a matrix (use as.matrix() to get just the matrix).

ATSPs can be transformed into (larger) symmetric TSPs using reformulate_ATSP_as_TSP().

Value

• ATSP() returns x as an object of class ATSP.

• n_of_cities() returns the number of cities in x.

• labels() returns a vector with the names of the cities in x.

Author(s)

Michael Hahsler

See Also

Other TSP: Concorde, ETSP(), TSPLIB, TSP(), insert_dummy(), reformulate_ATSP_as_TSP(), solve_TSP()

Examples

data <- matrix(runif(10^2), ncol = 10, dimnames = list(1:10, 1:10))

atsp <- ATSP(data)
atsp

## use some methods
n_of_cities(atsp)
labels(atsp)

## calculate a tour
tour <- solve_TSP(atsp, method = "nn")
tour

tour_length(tour)

image(atsp, tour)