On Mon, Sep 6, 2010 at 4:55 AM, Simon King <[email protected]> wrote:
> The remaining problem concerns the random generator of GAP. It behaves
> differently on T2 than on any other machine that I have access to.
My guess is that it is due to the endianness of the machine. For
example, check out this snippet from sage.misc.randstate:
# GAP's random number generator initialization
# (in integer.c, in FuncInitRandomMT) takes its
# seed as a string, then converts this string into
# an array of 32-bit integers just by casting the
# pointer. Thus, the result depends on the
# endianness of the machine. As a workaround, we
# swap the bytes in the string ourselves, so that
# GAP always gets the same array of integers.
If you're using GAP from withing Sage, you might just want to do
current_randstate().set_seed_gap() to initialize the random number
generators. Note that both of the following are reset:
prev_mersenne_seed = gap.Reset(gap.GlobalMersenneTwister,
mersenne_seed)
prev_classic_seed = gap.Reset(gap.GlobalRandomSource, classic_seed)
--Mike
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