[Numpy-discussion] randint for long type (permutations)

Will Woods will.woods@ynic.york.ac...
Thu Jun 14 07:37:54 CDT 2007


I want to choose a subset of all possible permutations of a sequence of 
length N, with each element of the subset unique. This is then going to 
be scattered across multiple machines using mpi. Since there is a 
one-to-one mapping between the integers in the range 0 <= x < N! and the 
possible permutations, one solution would be to choose M < N! integers 
randomly, check for uniqueness, and then scatter only the integers so 
that individual nodes can construct the permutations. However the 
integers need to be of type long, and randint doesn't work for numbers 
which cannot be converted to int. Any suggestions?


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