The files of the form *city<n>.lab* hold the gazateer data for the cities in the same order as *city<n>.ll* so you can label the cities with their names. This is not needed to contruct the problem instance.

If *lon*[*c*] and *lat*[*c*] are the longitude and latitude entries of file *city<n>.ll* for city *c*, then the distance between two cities *x* and *y* in tenths of a kilometer would be:

- cos(

sin(

sin(

where

- acos() is the arccosine function,

or you can use the following code to convert a file named *city.ll* to a full *n* by *n* matrix in a file named *city.mtx*.

- cityread.c

- city200.ll (city200.lab)
- city300.ll (city300.lab)
- city400.ll (city400.lab)
- city500.ll (city500.lab)
- city600.ll (city600.lab)
- city750.ll (city750.lab)
- city1000.ll (city1000.lab)

For the asymmetric TSP problem generator developed by Bruno Repetto, click here.

Neil Simonetti