[Swift-devel] random seed generator?

[Ben Clifford]

On Wed, 25 Apr 2007, Veronika  V. Nefedova wrote:

> I know I've raised this question before and I had received several
> suggestions, but I am wondering what is the consensus on generating the random
> seed in swift? I needed it for MolDyn workflow (had to do some hacks for
> them), and I need it for the lqcd workflow too.
> For lqcd I need to change the random seed inside the input file at every loop
> step. What is the best way to proceed? I see a couple of options:
> 
> 1. have an external program generate the random seed and then call it from
> swift.
> 2. Have swift somehow generate the random seed
> 
> I am curious if option 2 is possible ?

>From a practical perspective, we could have a @random function which 
generates a random number - I'll make one.

>From a theoretical perspective, it changes the notion of reproducibility 
to be more deliberately non-deterministic; though this isn't the only 
source of such non-determinism. For example, different software versions 
will produce different outputs (for example, gif->jpeg encoders) that are 
'the same' under a weaker definition of 'sameness' that means 'they look 
the same to a person', and thus I guess your outputs would be 'the same' 
under a statistical definition.

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