Hello Angeliki,
GetConnections() takes time, but eight hours compared to 20 + 15 minutes for a network of 27.000 neurons seems very slow. I would definitely suggest that you try with
the newest NEST version, 3.5. NEST 2.20 is quite old by now and we have made a large number of improvements in the meantime.
NEST 3.5 allows parameterization of neurons and connections while they are created directly at the C++ level, which saves a lot of time (20 minutes to build a 27.000
neuron network seems slow). Depending on what kind of "manual" manipulation of synaptic weights you need to do, it might even be possible to include this in connection creation, so you can avoid GetConnections() altogether.
Best,
Hans Ekkehard
--
Prof. Dr. Hans Ekkehard Plesser
Department of Data Science
Faculty of Science and Technology
Norwegian University of Life Sciences
PO Box 5003, 1432 Aas, Norway
Phone +47 6723 1560
Email hans.ekkehard.plesser@nmbu.no
Home http://arken.nmbu.no/~plesser