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Re: RNG question
On Fri, 8 Aug 2008, Brian Gough wrote:
At Sun, 3 Aug 2008 19:28:52 -0400 (EDT),
Robert G. Brown wrote:
There are obviously several ways I can fix it so this never happens
again, but I thought before I implemented any of them I'd ask at least
if it is now expected that the rngs in the gsl are "frozen", or if there
is an ongoing possibility that more will be added?
Yes, I expect there will be some new ones (or corrections to existing
ones).
The other question I have is that at one point in time the maximum
number of rngs one could have was restricted by a macro in the sources
to be 100 (if I recall correctly -- I have a remark to that effect in my
own code's comments).
The macro is really an internal implementation detail and not intended
to be a limit (as far as I'm aware it's not publically accessible).
There are currently about 60 generators so if you wanted to give them
numbers 100 is too small but 1000 or 500 shouldn't be a problem.
I looked over the code again and decided that was probably true on my
own. I'm preparing to basically clone the types.c module but create a
larger vector of types. I'll then run through a loop to populated it
with the gsl ones, then add my own, in ranges.
Are future/new rngs going to always be added at the end (new numbers) or
will they get inserted in typed groupings? I ask because IIRC the new
MT's went in next to the original MT and displaced all the numbers.
This makes logical sense, but breaks code that has hard coded rng
numbers. I can make dieharder work either way, but to lock in the
numbers in dieharder in the latter case I have to work harder...;-).
rgb
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Robert G. Brown Phone(cell): 1-919-280-8443
Duke University Physics Dept, Box 90305
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Web: http://www.phy.duke.edu/~rgb
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