Dear Hans Ekkehard, We are not using mpi4py. We simply set the number of virtual processes at the begining of simulation:nest.total_num_virtual_procs = 32 for example

We want to collect weights of stdp synapses before and after the simulation. Getting connections however, we observed different source and target before and after we run the simulation. I suppose this is because GetConnections returns only a portion of connections but how to obtain all portions is not clear for us.

Best,Petia

On Tuesday, June 6, 2023 at 09:24:30 AM GMT+3, Hans Ekkehard Plesser hans.ekkehard.plesser@nmbu.no wrote:

Dear Petia,

On each MPI rank, GetConnections() will only collect connections for which the post-synaptic neuron is on that MPI rank. You then need to find a way to collect this information across ranks. If you only need that information for offline processing, it might be easiest to write the connection information to file from each rank and then collect across ranks (you probably don't want to store the result from GetConnections(), but rather get the status of the synapses and store that). As a starting point, you could take the

https://nest-simulator.readthedocs.io/en/v3.4/auto_examples/store_restore_ne...

example. There, connections (and neurons) are stored with

network= {}

network["n_vp"]= nest.total_num_virtual_procs

network["e_nrns"]=self.neurons.get(["V_m"], output="pandas")

network["i_nrns"]=self.neurons.get(["V_m"], output="pandas")

network["e_syns"]= nest.GetConnections(synapse_model="e_syn").get(

("source","target","weight"), output="pandas")

network["i_syns"]= nest.GetConnections(synapse_model="i_syn").get(

("source","target","weight"), output="pandas")

withopen(dump_filename,"wb")as f:

pickle.dump(network, f, pickle.HIGHEST_PROTOCOL)

You might not need the data on neurons, and you would have to write one file per MPI rank. Depending on your synapse type, you may want to store more parameters than source, target and weight.

If you need the information at runtime, you could try to use mpi4py to aggregate the connection information across ranks.

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@nmbu.no

Home http://arken.nmbu.no/~plesser

From: Petia Koprinkova pkoprinkova@yahoo.com Date: Monday, 5 June 2023 at 13:11 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] GetConnections in distributed simulation

Dear NEST Support team,

We are trying to get the weights of stdp synapses during a distributed simulation.

According to NEST documentation and our experience function GetConnections returns only local connections but not all connections in our model.

Could you please advise us how to get all connections in such a case?

Best regards,

Petia Koprinkova-Hristova _______________________________________________ NEST Users mailing list -- users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.org

Dear Jan, Thank you very much for exhaustive answer. We are using single mpi process (python3 sctipt.py) with given number of virtual processes. However, GetConnections returns different source neurons as well, e.g.: Before Simulate: source = [21, 21, 22, 23, 24,....]After Simulate: source=[23, 24, 24, 27,....] We've noticed that sources are ordered while targets are not but still there is some missmatch before and after simulation. I have to point out that our network is designed as 3D structure with stdp synapses generated based on the distance between each pair of neurons and with given probability as follows: conn_dict = {         'rule': 'pairwise_bernoulli',         'p': nest.spatial_distributions.exponential(nest.spatial.distance, beta = 50),         'mask': {'spherical': {'radius': 60}},         'allow_autapses': True,         'allow_multapses': False     }

We aim to obtain exact weights of the stdp synapses after presenting some input to the network and then to fix the weights so we appreciate your help very much. Best wishes,Petia

On Tuesday, June 6, 2023 at 12:14:30 PM GMT+3, Vogelsang, Jan j.vogelsang@fz-juelich.de wrote:

Dear Petia,

Are you invoking your simulation script using MPI (e.g. mpiexec python script.py) or are you just using a single process (e.g. python script.py)? In the latter case, increasing the number of virtual processes (using nest.total_num_virtual_procs) simply increases the number of threads used by that single process which is internally used for OpenMP shared-memory parallelization which therefore runs NEST in a non-distributed way.

When using a single process, GetConnections (if called without any parameters) returns all connections in the whole simulation. CallingGetConnections before and after the first call to Simulate (or Prepare) is indeed expected to return the connections in a different order. To massively increase the performance of the simulation, all connections are sorted by their corresponding source node prior to the first update cycle in the simulation.

If you want to collect weights for connections in the same order before and after the simulation, please run "nest.Prepare()" once before your first call toSimulate. While this call is redundant (as it will be called inside Simulate as well), it will ensure that all connections are already sorted. After your call to Prepare, you can call GetConnections to retrieve information about all connections in the correct order.

Please note that it is not yet possible to get precise STDP weights yet due to some internal optimizations, while the weight for most synapses will be correct and precise, it is not guaranteed to be the case for each individual synapse. If you need to get exact weights for individual synapses, please let me know, as I am currently actively working on that. If you are just interested in stochastic analysis of weights, you can safely assume that weights are sufficiently accurate across a whole population.

Best, Jan From: Petia Koprinkova pkoprinkova@yahoo.com Sent: Tuesday, June 6, 2023 10:38:38 AM To: NEST User Mailing List Subject: [NEST Users] Re: GetConnections in distributed simulation Dear Hans Ekkehard, We are not using mpi4py. We simply set the number of virtual processes at the begining of simulation:nest.total_num_virtual_procs = 32 for example

We want to collect weights of stdp synapses before and after the simulation. Getting connections however, we observed different source and target before and after we run the simulation. I suppose this is because GetConnections returns only a portion of connections but how to obtain all portions is not clear for us.

Best,Petia

On Tuesday, June 6, 2023 at 09:24:30 AM GMT+3, Hans Ekkehard Plesser hans.ekkehard.plesser@nmbu.no wrote:

Dear Petia,

On each MPI rank, GetConnections() will only collect connections for which the post-synaptic neuron is on that MPI rank. You then need to find a way to collect this information across ranks. If you only need that information for offline processing, it might be easiest to write the connection information to file from each rank and then collect across ranks (you probably don't want to store the result from GetConnections(), but rather get the status of the synapses and store that). As a starting point, you could take the

https://nest-simulator.readthedocs.io/en/v3.4/auto_examples/store_restore_ne...

example. There, connections (and neurons) are stored with

network = {}

network["n_vp"]= nest.total_num_virtual_procs

network["e_nrns"]=self.neurons.get(["V_m"], output="pandas")

network["i_nrns"]=self.neurons.get(["V_m"], output="pandas")

network["e_syns"]= nest.GetConnections(synapse_model="e_syn").get(

("source","target","weight"), output="pandas")

network["i_syns"]= nest.GetConnections(synapse_model="i_syn").get(

("source","target","weight"), output="pandas")

withopen(dump_filename,"wb")as f:

pickle.dump(network, f, pickle.HIGHEST_PROTOCOL)

You might not need the data on neurons, and you would have to write one file per MPI rank. Depending on your synapse type, you may want to store more parameters than source, target and weight.

If you need the information at runtime, you could try to use mpi4py to aggregate the connection information across ranks.

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@nmbu.no

Home http://arken.nmbu.no/~plesser

From: Petia Koprinkova pkoprinkova@yahoo.com Date: Monday, 5 June 2023 at 13:11 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] GetConnections in distributed simulation

Dear NEST Support team,

We are trying to get the weights of stdp synapses during a distributed simulation.

According to NEST documentation and our experience function GetConnections returns only local connections but not all connections in our model.

Could you please advise us how to get all connections in such a case?

Best regards,

Petia Koprinkova-Hristova _______________________________________________ NEST Users mailing list -- users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.org

------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Stefan Müller Geschaeftsfuehrung: Prof. Dr.-Ing. Wolfgang Marquardt (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Dr. Ir. Pieter Jansens, Prof. Dr. Astrid Lambrecht, Prof. Dr. Frauke Melchior ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ _______________________________________________ NEST Users mailing list -- users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.org

Hi Petia,

Given that the comparison of sets suggested by Hans Ekkehard are equal, you can, for instance, use the following to sort the connections for easier inspection before and after simulation:

# Retrieve SynapseCollection syn_collection = nest.GetConnections()

# Create DataFrame from parameter dictionary of the connections df_conns = pandas.DataFrame.from_dict(syn_collection.get())

# Sort connections by, in decreasing order of priority, the # target thread id, source node id and target node id df_conns.sort_values( by=["target_thread", "source", "target"], ignore_index=True, inplace=True )

print(df_conns)

Best, Nicolai ________________________________ From: Hans Ekkehard Plesser hans.ekkehard.plesser@nmbu.no Sent: 06 June 2023 12:27 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] Re: GetConnections in distributed simulation

Hello Petia,

If you call GetConnections() once before and once after Simulate() and get source and target lists, and for source-target pairs, then the before and after source-target pairs should be identical except for ordering, so comparing them as sets they should compare equal. If not, something would be seriously wrong.

As for the precise weight of synapses at a given time point, NEST only updates synaptic weights when a spike passes through, so for now you will get the weight of the synapse at the time the most recent spike passed the synapse.

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@nmbu.nomailto:hans.ekkehard.plesser@nmbu.no

Home http://arken.nmbu.no/~plesser

From: Petia Koprinkova pkoprinkova@yahoo.com Date: Tuesday, 6 June 2023 at 12:18 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] Re: GetConnections in distributed simulation

Dear Jan,

Thank you very much for exhaustive answer.

We are using single mpi process (python3 sctipt.py) with given number of virtual processes. However, GetConnections returns different source neurons as well, e.g.:

Before Simulate: source = [21, 21, 22, 23, 24,....]

After Simulate: source=[23, 24, 24, 27,....]

We've noticed that sources are ordered while targets are not but still there is some missmatch before and after simulation.

I have to point out that our network is designed as 3D structure with stdp synapses generated based on the distance between each pair of neurons and with given probability as follows:

conn_dict = { 'rule': 'pairwise_bernoulli', 'p': nest.spatial_distributions.exponential(nest.spatial.distance, beta = 50), 'mask': {'spherical': {'radius': 60}}, 'allow_autapses': True, 'allow_multapses': False }

We aim to obtain exact weights of the stdp synapses after presenting some input to the network and then to fix the weights so we appreciate your help very much.

Best wishes,

Petia

On Tuesday, June 6, 2023 at 12:14:30 PM GMT+3, Vogelsang, Jan j.vogelsang@fz-juelich.de wrote:

Dear Petia,

Are you invoking your simulation script using MPI (e.g. mpiexec python script.py) or are you just using a single process (e.g. python script.py)? In the latter case, increasing the number of virtual processes (using nest.total_num_virtual_procs) simply increases the number of threads used by that single process which is internally used for OpenMP shared-memory parallelization which therefore runs NEST in a non-distributed way.

When using a single process, GetConnections (if called without any parameters) returns all connections in the whole simulation. Calling GetConnections before and after the first call to Simulate (or Prepare) is indeed expected to return the connections in a different order. To massively increase the performance of the simulation, all connections are sorted by their corresponding source node prior to the first update cycle in the simulation.

If you want to collect weights for connections in the same order before and after the simulation, please run "nest.Prepare()" once before your first call to Simulate. While this call is redundant (as it will be called inside Simulate as well), it will ensure that all connections are already sorted. After your call to Prepare, you can call GetConnections to retrieve information about all connections in the correct order.

Please note that it is not yet possible to get precise STDP weights yet due to some internal optimizations, while the weight for most synapses will be correct and precise, it is not guaranteed to be the case for each individual synapse. If you need to get exact weights for individual synapses, please let me know, as I am currently actively working on that. If you are just interested in stochastic analysis of weights, you can safely assume that weights are sufficiently accurate across a whole population.

Best, Jan

________________________________

From: Petia Koprinkova pkoprinkova@yahoo.com Sent: Tuesday, June 6, 2023 10:38:38 AM To: NEST User Mailing List Subject: [NEST Users] Re: GetConnections in distributed simulation

Dear Hans Ekkehard,

We are not using mpi4py. We simply set the number of virtual processes at the begining of simulation:

nest.total_num_virtual_procs = 32 for example

We want to collect weights of stdp synapses before and after the simulation. Getting connections however, we observed different source and target before and after we run the simulation. I suppose this is because GetConnections returns only a portion of connections but how to obtain all portions is not clear for us.

Best,

Petia

On Tuesday, June 6, 2023 at 09:24:30 AM GMT+3, Hans Ekkehard Plesser hans.ekkehard.plesser@nmbu.no wrote:

Dear Petia,

On each MPI rank, GetConnections() will only collect connections for which the post-synaptic neuron is on that MPI rank. You then need to find a way to collect this information across ranks. If you only need that information for offline processing, it might be easiest to write the connection information to file from each rank and then collect across ranks (you probably don't want to store the result from GetConnections(), but rather get the status of the synapses and store that). As a starting point, you could take the

https://nest-simulator.readthedocs.io/en/v3.4/auto_examples/store_restore_ne...

example. There, connections (and neurons) are stored with

network = {}

network["n_vp"] = nest.total_num_virtual_procs

network["e_nrns"] = self.neurons.get(["V_m"], output="pandas")

network["i_nrns"] = self.neurons.get(["V_m"], output="pandas")

network["e_syns"] = nest.GetConnections(synapse_model="e_syn").get(

("source", "target", "weight"), output="pandas")

network["i_syns"] = nest.GetConnections(synapse_model="i_syn").get(

("source", "target", "weight"), output="pandas")

with open(dump_filename, "wb") as f:

pickle.dump(network, f, pickle.HIGHEST_PROTOCOL)

You might not need the data on neurons, and you would have to write one file per MPI rank. Depending on your synapse type, you may want to store more parameters than source, target and weight.

If you need the information at runtime, you could try to use mpi4py to aggregate the connection information across ranks.

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@nmbu.nomailto:hans.ekkehard.plesser@nmbu.no

Home http://arken.nmbu.no/~plesser

From: Petia Koprinkova pkoprinkova@yahoo.com Date: Monday, 5 June 2023 at 13:11 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] GetConnections in distributed simulation

Dear NEST Support team,

We are trying to get the weights of stdp synapses during a distributed simulation.

According to NEST documentation and our experience function GetConnections returns only local connections but not all connections in our model.

Could you please advise us how to get all connections in such a case?

Best regards,

Petia Koprinkova-Hristova

_______________________________________________ NEST Users mailing list -- users@nest-simulator.orgmailto:users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.orgmailto:users-leave@nest-simulator.org

------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Stefan Müller Geschaeftsfuehrung: Prof. Dr.-Ing. Wolfgang Marquardt (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Dr. Ir. Pieter Jansens, Prof. Dr. Astrid Lambrecht, Prof. Dr. Frauke Melchior ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------

_______________________________________________ NEST Users mailing list -- users@nest-simulator.orgmailto:users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.orgmailto:users-leave@nest-simulator.org

Hi Petia,

The connections are actually returned in a somewhat arbitrary order by GetConnections calls in multithreaded simulations, which can be seen by this trivial example:

import nest

nest.set(total_num_virtual_procs=4)

nrns = nest.Create("iaf_psc_alpha", 4)

nest.Connect(nrns, nrns, "one_to_one")

conns_before_sim = nest.GetConnections()

nest.Simulate(10.0)

conns_after_sim = nest.GetConnections()

sources_before_sim = conns_before_sim.get("source") sources_after_sim = conns_after_sim.get("source")

print(f"{sources_before_sim=}") print(f"{sources_after_sim=}")

# Output: sources_before_sim=[3, 1, 2, 4] sources_after_sim=[4, 2, 3, 1]

So, I would not be too worried about the different ordering. I would, however, still do the set comparison as a sanity check and then just sort the connections for easier inspection and comparison 🙂

Best, Nicolai ________________________________ From: Petia Koprinkova pkoprinkova@yahoo.com Sent: 06 June 2023 13:04 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] Re: GetConnections in distributed simulation

Thank you very much Nicolai and Hans Ekkehard! We will try your proposal. Anyway it seems that the sources are ordered so it is suspictious to have such difference even at the begining of the list.

Best, Petia

On Tuesday, June 6, 2023 at 01:51:03 PM GMT+3, Nicolai Haug nicolai.haug@nmbu.no wrote:

Hi Petia,

Given that the comparison of sets suggested by Hans Ekkehard are equal, you can, for instance, use the following to sort the connections for easier inspection before and after simulation:

# Retrieve SynapseCollection syn_collection = nest.GetConnections()

# Create DataFrame from parameter dictionary of the connections df_conns = pandas.DataFrame.from_dict(syn_collection.get())

# Sort connections by, in decreasing order of priority, the # target thread id, source node id and target node id df_conns.sort_values( by=["target_thread", "source", "target"], ignore_index=True, inplace=True )

print(df_conns)

Best, Nicolai ________________________________ From: Hans Ekkehard Plesser hans.ekkehard.plesser@nmbu.no Sent: 06 June 2023 12:27 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] Re: GetConnections in distributed simulation

Hello Petia,

If you call GetConnections() once before and once after Simulate() and get source and target lists, and for source-target pairs, then the before and after source-target pairs should be identical except for ordering, so comparing them as sets they should compare equal. If not, something would be seriously wrong.

As for the precise weight of synapses at a given time point, NEST only updates synaptic weights when a spike passes through, so for now you will get the weight of the synapse at the time the most recent spike passed the synapse.

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@nmbu.nomailto:hans.ekkehard.plesser@nmbu.no

Home http://arken.nmbu.no/~plesser

From: Petia Koprinkova pkoprinkova@yahoo.com Date: Tuesday, 6 June 2023 at 12:18 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] Re: GetConnections in distributed simulation

Dear Jan,

Thank you very much for exhaustive answer.

We are using single mpi process (python3 sctipt.py) with given number of virtual processes. However, GetConnections returns different source neurons as well, e.g.:

Before Simulate: source = [21, 21, 22, 23, 24,....]

After Simulate: source=[23, 24, 24, 27,....]

We've noticed that sources are ordered while targets are not but still there is some missmatch before and after simulation.

I have to point out that our network is designed as 3D structure with stdp synapses generated based on the distance between each pair of neurons and with given probability as follows:

conn_dict = { 'rule': 'pairwise_bernoulli', 'p': nest.spatial_distributions.exponential(nest.spatial.distance, beta = 50), 'mask': {'spherical': {'radius': 60}}, 'allow_autapses': True, 'allow_multapses': False }

We aim to obtain exact weights of the stdp synapses after presenting some input to the network and then to fix the weights so we appreciate your help very much.

Best wishes,

Petia

On Tuesday, June 6, 2023 at 12:14:30 PM GMT+3, Vogelsang, Jan j.vogelsang@fz-juelich.de wrote:

Dear Petia,

Are you invoking your simulation script using MPI (e.g. mpiexec python script.py) or are you just using a single process (e.g. python script.py)? In the latter case, increasing the number of virtual processes (using nest.total_num_virtual_procs) simply increases the number of threads used by that single process which is internally used for OpenMP shared-memory parallelization which therefore runs NEST in a non-distributed way.

When using a single process, GetConnections (if called without any parameters) returns all connections in the whole simulation. Calling GetConnections before and after the first call to Simulate (or Prepare) is indeed expected to return the connections in a different order. To massively increase the performance of the simulation, all connections are sorted by their corresponding source node prior to the first update cycle in the simulation.

If you want to collect weights for connections in the same order before and after the simulation, please run "nest.Prepare()" once before your first call to Simulate. While this call is redundant (as it will be called inside Simulate as well), it will ensure that all connections are already sorted. After your call to Prepare, you can call GetConnections to retrieve information about all connections in the correct order.

Please note that it is not yet possible to get precise STDP weights yet due to some internal optimizations, while the weight for most synapses will be correct and precise, it is not guaranteed to be the case for each individual synapse. If you need to get exact weights for individual synapses, please let me know, as I am currently actively working on that. If you are just interested in stochastic analysis of weights, you can safely assume that weights are sufficiently accurate across a whole population.

Best, Jan

________________________________

From: Petia Koprinkova pkoprinkova@yahoo.com Sent: Tuesday, June 6, 2023 10:38:38 AM To: NEST User Mailing List Subject: [NEST Users] Re: GetConnections in distributed simulation

Dear Hans Ekkehard,

We are not using mpi4py. We simply set the number of virtual processes at the begining of simulation:

nest.total_num_virtual_procs = 32 for example

We want to collect weights of stdp synapses before and after the simulation. Getting connections however, we observed different source and target before and after we run the simulation. I suppose this is because GetConnections returns only a portion of connections but how to obtain all portions is not clear for us.

Best,

Petia

On Tuesday, June 6, 2023 at 09:24:30 AM GMT+3, Hans Ekkehard Plesser hans.ekkehard.plesser@nmbu.no wrote:

Dear Petia,

On each MPI rank, GetConnections() will only collect connections for which the post-synaptic neuron is on that MPI rank. You then need to find a way to collect this information across ranks. If you only need that information for offline processing, it might be easiest to write the connection information to file from each rank and then collect across ranks (you probably don't want to store the result from GetConnections(), but rather get the status of the synapses and store that). As a starting point, you could take the

https://nest-simulator.readthedocs.io/en/v3.4/auto_examples/store_restore_ne...

example. There, connections (and neurons) are stored with

network = {}

network["n_vp"] = nest.total_num_virtual_procs

network["e_nrns"] = self.neurons.get(["V_m"], output="pandas")

network["i_nrns"] = self.neurons.get(["V_m"], output="pandas")

network["e_syns"] = nest.GetConnections(synapse_model="e_syn").get(

("source", "target", "weight"), output="pandas")

network["i_syns"] = nest.GetConnections(synapse_model="i_syn").get(

("source", "target", "weight"), output="pandas")

with open(dump_filename, "wb") as f:

pickle.dump(network, f, pickle.HIGHEST_PROTOCOL)

You might not need the data on neurons, and you would have to write one file per MPI rank. Depending on your synapse type, you may want to store more parameters than source, target and weight.

If you need the information at runtime, you could try to use mpi4py to aggregate the connection information across ranks.

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@nmbu.nomailto:hans.ekkehard.plesser@nmbu.no

Home http://arken.nmbu.no/~plesser

From: Petia Koprinkova pkoprinkova@yahoo.com Date: Monday, 5 June 2023 at 13:11 To: NEST User Mailing List users@nest-simulator.org Subject: [NEST Users] GetConnections in distributed simulation

Dear NEST Support team,

We are trying to get the weights of stdp synapses during a distributed simulation.

According to NEST documentation and our experience function GetConnections returns only local connections but not all connections in our model.

Could you please advise us how to get all connections in such a case?

Best regards,

Petia Koprinkova-Hristova

_______________________________________________ NEST Users mailing list -- users@nest-simulator.orgmailto:users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.orgmailto:users-leave@nest-simulator.org

------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Stefan Müller Geschaeftsfuehrung: Prof. Dr.-Ing. Wolfgang Marquardt (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Dr. Ir. Pieter Jansens, Prof. Dr. Astrid Lambrecht, Prof. Dr. Frauke Melchior ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------

_______________________________________________ NEST Users mailing list -- users@nest-simulator.orgmailto:users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.orgmailto:users-leave@nest-simulator.org

_______________________________________________ NEST Users mailing list -- users@nest-simulator.orgmailto:users@nest-simulator.org To unsubscribe send an email to users-leave@nest-simulator.orgmailto:users-leave@nest-simulator.org