ASA113
A Transfer Algorithm for Non-hierarchical Classification

ASA113 is a FORTRAN90 library which divides M points in N dimensions into K clusters seeking the division which minimizes a user-defined criterion, by Banfield and Bassill.

ASA113 is in some sense a generalization of the K-means algorithm, because the user is allowed to choose the criterion function to be minimized, and because the algorithm considers both all possible transfers of an object from one class to another, and all possible exchanges that swap two objects.

However, because it is not a K-means algorithm, there is a significant amount of work off-loaded onto the user, and the task of evaluating the change in the criterion function can be far more expensive than in the K-means setting, and the consideration of all possible exchanges can result in an explosion in the running time for large data sets.

Thus, the algorithm should not be the first choice if a K-means calculation is really what is desired, and it may be far too expensive to use if the size of the data set is significant.

ASA113 is Applied Statistics Algorithm 113.

Languages:

ASA113 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

ASA058, a FORTRAN90 library which carries out the K-means algorithm for clustering data.

ASA136, a FORTRAN90 library which carries out the K-means algorithm for clustering data.

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

CITIES, a dataset directory which contains a number of city distance datasets.

KMEANS, a FORTRAN90 library which contains several implementations of the H-Means and K-Means clustering algorithms.

LAU_NP, a FORTRAN90 library which contains heuristic algorithms for the K-center and K-median problems.

SPAETH, a FORTRAN90 library which clusters data according to various principles.

SPAETH, a dataset directory which contains test data for clustering.

SPAETH2, a FORTRAN90 library which can cluster data according to various principles.

SPAETH2, a dataset directory which contains test data for clustering.

Author:

Original FORTRAN77 version by Banfield and Bassill; FORTRAN90 version by John Burkardt.

Reference:

1. Colin Banfield, LC Bassill,
   Algorithm AS 113: A transfer for non-hierarchichal classification,
   Applied Statistics,
   Volume 26, Number 2, 1977, pages 206-210.

Source Code:

• asa113.f90, the source code.

Examples and Tests:

• asa113_test.f90, a sample calling program.
• points_100.txt, a sample dataset of 100 points in 2D, to be arranged into 5 classes.
• asa113_test.txt, the output file.

List of Routines:

• SWAP interchanges objects between different classes to improve a criterion.
• TIMESTAMP prints out the current YMDHMS date as a timestamp.
• TRNSFR transfers objects between classes to improve a criterion.

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