ASA113
A Transfer Algorithm for Non-hierarchical Classification

ASA113 is a MATLAB library which divides M points in N dimensions into K clusters seeking the division which minimizes a user-defined criterion.

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. Source code for many Applied Statistics Algorithms is available through STATLIB.

Related Data and Programs:

ASA058 is a MATLAB library which carries out the K-means algorithm for clustering data.

ASA113 is also available in a C++ version and a FORTRAN77 version and a FORTRAN90 version.

ASA136 is a MATLAB library which carries out the K-means algorithm for clustering data.

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

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

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

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

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

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

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

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

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:

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

Examples and Tests:

• asa113_test.m, a sample calling program.
• asa113_test01.m, tests TRNSFR and SWAP
• crswap.m, determines the effect of a swap of two objects.
• crtran.m, determines the effect of a transfer of an object.
• points_100.txt, a sample dataset of 100 points in 2D, to be arranged into 5 classes.
• asa113_test_output.txt, the output file.

List of Routines:

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