Dear NEST Users and Developers!
After a long and demanding process, we merged pull request #1549 into the NEST master
branch earlier this afternoon. It replaces the old random number generator suite in NEST
completely with a new one based on the C++ Standard Library and also providing generators
from the Random123 library, including cryptographic generators.
The most important change for users is that you can now much more easily seed generators
and change the type of random number generator used. To seed, you only need a single
seed—NEST will take care of everything else:
is all it takes. To select a different RNG type, use
To see all available RNG types, use
For more information, see
I hope this change will motivate everyone to even more systematically explore their models
with a wide range of seeds and with different random number generator types.
Existing simulation scripts, which otherwise are compatible with NEST master will only
need to change the part of the script related to seeding and RNG selection.
Because we now use a completely different internal architecture to provide random numbers,
the actual sequence of random numbers provided will be different from before. This means
that it is not possible to exactly reproduce spike trains obtained with the old RNG setup.
Statistically, though, results shall be identical. If you should observe any unexpected
deviations in results after switching to the new RNG scheme, please contact us!
I would like to thank everyone who has contributed to this effort over a long time,
especially Håkon and Jochen for their design and development work, and Johanna and Jasper
for generating a lot of test data.
With the new RNGs, the last major component for NEST3 is now integrated into the NEST
master branch and we are very optimistic to finally make the NEST3 release before this
Prof. Dr. Hans Ekkehard Plesser
Head, Department of Data Science
Faculty of Science and Technology
Norwegian University of Life Sciences
PO Box 5003, 1432 Aas, Norway
Phone +47 6723 1560