Hi Xavier, I am afraid the documentation for NEST 2.18 and 2.20 is misleading in this respect. The "binary" option has no effect and should have been removed long ago (it sets the ios::binary flag when opening the file, but that has no significant consequences). If you want to write spikes in binary format, you need to switch to the current NEST Master, see https://nest-simulator.readthedocs.io/en/latest/guides/recording_from_simul… Best, Hans Ekkehard -- 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 Email hans.ekkehard.plesser(a)nmbu.no Home http://arken.nmbu.no/~plesser On 09/04/2021, 22:28, "xotazu(a)cvc.uab.es" <xotazu(a)cvc.uab.es> wrote: This simple code generates text gdf files. What am I doing wrong? import nest nest.SetKernelStatus({"overwrite_files": True}) poiss = nest.Create("poisson_generator") nest.SetStatus(poiss, {"rate": float(100.0)}) parrots = nest.Create("parrot_neuron") sdetector = nest.Create("spike_detector") nest.SetStatus(sdetector, {"withgid": True, "withtime": True, "to_file": True, "label": "receive", "file_extension": "spikes", "binary":True}) nest.Connect(poiss, parrots, 'one_to_one', {"weight":1.0, "delay": 2.0}) nest.Connect(parrots, sdetector) nest.Simulate(1000.0) _______________________________________________ NEST Users mailing list -- users(a)nest-simulator.org To unsubscribe send an email to users-leave(a)nest-simulator.org