TSP_IO
Read or Write Traveling Salesman Problem (TSP) Files

TSP_IO is a FORTRAN90 library which is intended to be used to read or write some of the formats used in TSPLIB, a collection of traveling salesman problems stored in a particular format known as "TSP".

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

TSP_IO is available in a FORTRAN90 version.

Related Data and Programs:

CITIES, a dataset directory which contains sets of information about cities and the distances between them;

CITIES, a FORTRAN90 library which handles various problems associated with a set of "cities" on a map.

TSP, a dataset directory which contains test data for the traveling salesperson problem;

TSP_BRUTE, a FORTRAN90 program which reads a file of city-to-city distances and solves the traveling salesperson problem, using brute force.

TSP_LAU, a FORTRAN90 library which implements a heuristic algorithm for the solution of the traveling salesperson problem, by Hang Tong Lau.

Reference:

1. Gerhard Reinelt,
   TSPLIB - A Traveling Salesman Problem Library,
   ORSA Journal on Computing,
   Volume 3, Number 4, Fall 1991, pages 376-384.

Source Code:

• tsp_io.f90, the source code.

Examples and Tests:

• tsp_io_test.f90, a sample calling program.
• tsp_io_test.txt, the output file.

P01 is a small example of 15 cities.

• p01.tsp, the TSP file.
• p01_d.txt, the distance table file created by TSP_IO_PRB.

ATT48 is a classic example of 48 cities.

• att48.tsp, the TSP file.
• att48_d.txt, the distance table file created by TSP_IO_PRB.

List of Routines:

• CH_CAP capitalizes a single character.
• GET_UNIT returns a free FORTRAN unit number.
• I4MAT_PRINT prints an I4MAT.
• I4MAT_PRINT_SOME prints some of an I4MAT.
• I4MAT_WRITE writes an I4MAT file.
• PSEUDO_EUCLIDEAN_DISTANCE computes the distance used for the ATT example.
• S_EQI is a case insensitive comparison of two strings for equality.
• S_TO_I4 reads an integer value from a string.
• S_WORD_EXTRACT_FIRST extracts the first word from a string.
• TEXT_SPLIT uses a colon to locate the keyword and field in a line of text.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• TSP_EDGE_WEIGHT_READ reads the edge weights of a TSP file.
• TSP_HEADER_READ reads the header of a TSP file.

You can go up one level to the FORTRAN90 source codes.