ASA172
Generation of all multi-indices in a given range

ASA172 is a FORTRAN90 library which generates all multidimensional indices in a given range. simulating the behavior of an arbitrary number of nested loops, by OFlaherty and MacKenzie.

If the number of dimensions was known in advance, such an operation could be carried out by the corresponding set of nested loops. For example, in 3D:

        do i = i1, i2
          do j = j1, j2
            do k = k1, k2
              (I,J,K) is an index in the range.
            end do
          end do
        end do
      

ASA172 is Applied Statistics Algorithm 172.

Languages:

ASA172 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

SUBSET, a FORTRAN90 library which enumerates combinations, partitions, subsets, index sets, trees, and other combinatorial objects.

Author:

Original FORTRAN77 version by M OFlaherty, G MacKenzie; FORTRAN90 version by John Burkardt.

Reference:

1. M OFlaherty, G MacKenzie,
   Algorithm AS 172: Direct Simulation of Nested Fortran DO-LOOPS,
   Applied Statistics,
   Volume 31, Number 1, 1982, pages 71-74.

Source Code:

• asa172.f90, the source code.

Examples and Tests:

• asa172_test.f90, a sample calling program.
• asa172_test.txt, the output file.

List of Routines:

• SIMDO generates multi-indices, simulating nested DO-loops.
• TIMESTAMP prints out the current YMDHMS date as a timestamp.

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