TOMS515
K subsets of an N set

TOMS515 is a Python library which lists the subsets of size K selected from a set of size N, by Bill Buckles, Matthew Lybanon.

Languages:

TOMS515 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Data and Programs:

SUBSET, a Python library which enumerates combinations, partitions, subsets, index sets, and other combinatorial objects.

Author:

Original FORTRAN77 version by Bill Buckles, Matthew Lybanon. Python version by John Burkardt.

Reference:

1. Bill Buckles, Matthew Lybanon,
   Algorithm 515: Generation of a Vector from the Lexicographical Index,
   ACM Transactions on Mathematical Software,
   Volume 3, Number 2, June 1977, pages 180-182.

Source Code:

• comb.py selects a subset of order P from a set of order N.
• gamma_log_values.py returns selected values of the logarithm of the gamma function.
• i4_choose.py computes the binomial coefficient.
• i4_choose_check.py reports whether the binomial coefficient can be computed.
• i4_uniform_ab.py returns a scaled pseudorandom I4 between A and B.
• r8_gamma_log.py evaluates the logarithm of the gamma function.
• timestamp.py prints the current YMDHMS date as a time stamp.

• toms515_test.py, calls all the tests.
• toms515_test.sh, runs all the tests.
• toms515_test.txt, the output from a run of the sample program.

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