asa172, a FORTRAN90 code 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
One feature of this code, though, is that it can generate all such indexes
for an arbitrary number of dimensions.
The code is Applied Statistics Algorithm 172.
The computer code and data files described and made available on this web page are distributed under the MIT license
asa172 is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.
SUBSET, a FORTRAN90 code which enumerates combinations, partitions, subsets, index sets, trees, and other combinatorial objects.
Original FORTRAN77 version by M OFlaherty, G MacKenzie; FORTRAN90 version by John Burkardt.