Gilles created RNG-20:
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Summary: Initial state diversity
Key: RNG-20
URL: https://issues.apache.org/jira/browse/RNG-20
Project: Commons RNG
Issue Type: Improvement
Reporter: Gilles
Assignee: Gilles
Priority: Minor
Fix For: 1.0
A generator usually _assumes_ that its initial state is "sufficiently diverse"
for it to perform correctly.
For example, it is known that some algorithms (e.g. "Mersenne Twister") will be
"stuck" by the all-zero state.
To ensure diversity when the seed (passed by the user) contains less
information than the state can hold, {{SeedFactory}} provides a {{fillState}}
method to be called from within the {{setSeedInternal}} method of an RNG
implementation.
In this ticket, it is proposed that the actual code (for replacing zeroes in
the initial state) is inspired from the one that already existed in class
{{AbstractWell}}.
Note: neither the code in {{AbstractWell}} nor another code, in
{{MersenneTwister}} and {{MersenneTwister64}} (with a similar purpose), will
be replaced by a call to {{fillState}} because for those algorithms, the
filling procedure is part of the reference code (and is thus necessary in order
to reproduce the exact same output).
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