25 May
2022
25 May
'22
5:47 p.m.
Dear Nest community,
I should import numerical data (not spiking data) obtained from a dynamic simulator called
CoppeliaSim (ex VRep) into a Nest script. To do this I thought of using a ROS subscriber
node that receives the data using a topic. I ask you, how do I interface Nest with Ros in
order to import the data?
Greetings,
Except
25 May
25 May
6:03 p.m.
Dear Salvatore,
first not a direct answer to your question, but if you are flexible and
like to use NEST with a physics simulation via ROS interface you may
want to check out the Neurorobotics Platform
(https://zenodo.org/record/3571242) that connects NEST with Gazebo as a
physics simulator via a ROS topics and a python interface. You can
request an account on our website www.neurorobotics.net and try out the
platform online without installation, but then also everything is open
source and you can tweak it as you like.
More precisely answering your question: The easiest solution would
probably be to use NEST in python, and then in the same python script
set up your ROS publisher that sends data over to your ROS subscriber in
CoppeliaSim. You will most likely need a transformation from spike train
data to float values in order to control anything in your physics
simulation, would be much easier to do this conversion before you send
it over ROS topics. In the Neurorobotics Platform we use leaky-integrate
and fire neurons with infinite threshold and read out its membrane
voltage as a single float value in order to get a moving average of the
spike data, something like an average spike rate. But this is only one
possible solutions, it really depends on how your network looks like and
what you like to do in your physics simulator.
[not a NEST developer, but working on the Neurorobotics Platform and its
NEST integration for embodied spiking neural simulations]
Best,
Benedikt
On 25.05.22 17:47, salvatore.taffara(a)phd.unict.it wrote:
Dear Nest community,
I should import numerical data (not spiking data) obtained from a dynamic simulator
called CoppeliaSim (ex VRep) into a Nest script. To do this I thought of using a ROS
subscriber node that receives the data using a topic. I ask you, how do I interface Nest
with Ros in order to import the data?
Greetings,
Except
_______________________________________________
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To unsubscribe send an email to users-leave(a)nest-simulator.org
--
Benedikt Feldotto, M.Sc.
Neurorobotics - Human Brain Project
Informatics 6 - Chair of Robotics, Artificial Intelligence and Real-Time Systems
Technical University of Munich
www.ce.cit.tum.de/air/people/benedikt-feldotto-msc/
Boltzmannstraße 3
85748 Garching bei München
Germany
6:09 p.m.
"The easiest solution would probably be to use NEST in python, and then in the same
python script set up your ROS publisher that sends data over to your ROS subscriber in
CoppeliaSim"
How can I use Ros in a Nest script if in Nest there is not a Ros interface with API
functions?
6:46 p.m.
Have a look at this tutorial on how to write a ROS publisher in a python
script
http://wiki.ros.org/ROS/Tutorials/WritingPublisherSubscriber%28python%29
In the same script you can then also import NEST (import nest) and set
up your network.
Be aware that simulations with this setup will not be deterministic,
since both physics simulation in CopeliaSim and neural simulation in
NEST just take as long as they need for one simulation step, and this
depends heavily on the computer performance and model/network
implemented. You would need to step both CopeliaSim and NEST in order to
achieve deterministic simulations, but I am not sure if and how this
would work with CopeliaSim.
Best,
Benedikt
On 25.05.22 18:09, salvatore.taffara(a)phd.unict.it wrote:
"The easiest solution would probably be to use
NEST in python, and then in the same python script set up your ROS publisher that sends
data over to your ROS subscriber in CoppeliaSim"
How can I use Ros in a Nest script if in Nest there is not a Ros interface with API
functions?
_______________________________________________
NEST Users mailing list -- users(a)nest-simulator.org
To unsubscribe send an email to users-leave(a)nest-simulator.org
--
Benedikt Feldotto, M.Sc.
Neurorobotics - Human Brain Project
Informatics 6 - Chair of Robotics, Artificial Intelligence and Real-Time Systems
Technical University of Munich
www.ce.cit.tum.de/air/people/benedikt-feldotto-msc/
Boltzmannstraße 3
85748 Garching bei München
Germany
7:54 p.m.
If I compile the Subscriber in which there is the "import nest" command I
obtain:
salvo@salvo-Aspire-GX-781:~$ rosrun pacchetto_ros sub_vrep.py
Traceback (most recent call last):
File "/home/salvo/Desktop/ros_ws/src/pacchetto_ros/scripts/sub_vrep.py", line
5, in <module>
import vrep
ImportError: No module named vrep
8:19 p.m.
Sorry, the correct output when I use "import nest" in the Subscriber is:
salvo@salvo-Aspire-GX-781:~/Desktop/ros_ws/src/pacchetto_ros/scripts$ rosrun pacchetto_ros
sub_vrep.py
Traceback (most recent call last):
File "/home/salvo/Desktop/ros_ws/src/pacchetto_ros/scripts/sub_vrep.py", line
5, in <module>
import nest
File "/usr/lib/python3.6/dist-packages/nest/__init__.py", line 26, in
<module>
from . import ll_api # noqa
File "/usr/lib/python3.6/dist-packages/nest/ll_api.py", line 72, in
<module>
from . import pynestkernel as kernel # noqa
ImportError: dynamic module does not define init function (initpynestkernel)
26 May
26 May
11:02 a.m.
The problem is maybe due to the fact that to import nest i have to use python3 but Melodic
is based on python2...
11:14 a.m.
If I use the rosrun command I have:
salvo@salvo-Aspire-GX-781:~/Desktop/ros_ws/src/pacchetto_ros/scripts$ rosrun
pacchetto_ros
sub_vrep.py
Traceback (most recent call last):
File "/home/salvo/Desktop/ros_ws/src/pacchetto_ros/scripts/sub_vrep.py", line
5, in <module>
import nest
File "/usr/lib/python3.6/dist-packages/nest/__init__.py", line 26, in
<module>
from . import ll_api # noqa
File "/usr/lib/python3.6/dist-packages/nest/ll_api.py", line 72, in
<module>
from . import pynestkernel as kernel # noqa
ImportError: dynamic module does not define init function (initpynestkernel)
The problem maybe is due to the fact that to import nest i have to use python3 but Melodic
is based on python2...
30 May
30 May
4:47 p.m.
Hi!
NEST 3.x (which is definitely what you should use) is indeed Python 3
only. Python 2 has been dead now since two and a half years... Here's
an article on how to build ROS with support for Python 3:
https://www.miguelalonsojr.com/blog/robotics/ros/python3/2019/08/20/ros-mel…
Cheers,
Jochen!
On 26.05.22 11:14, salvatore.taffara(a)phd.unict.it wrote:
If I use the rosrun command I have:
salvo@salvo-Aspire-GX-781:~/Desktop/ros_ws/src/pacchetto_ros/scripts$ rosrun
pacchetto_ros
sub_vrep.py
Traceback (most recent call last):
File "/home/salvo/Desktop/ros_ws/src/pacchetto_ros/scripts/sub_vrep.py",
line
5, in <module>
import nest
File "/usr/lib/python3.6/dist-packages/nest/__init__.py", line 26, in
<module>
from . import ll_api # noqa
File "/usr/lib/python3.6/dist-packages/nest/ll_api.py", line 72, in
<module>
from . import pynestkernel as kernel # noqa
ImportError: dynamic module does not define init function (initpynestkernel)
The problem maybe is due to the fact that to import nest i have to use python3 but
Melodic is based on python2...
_______________________________________________
NEST Users mailing list -- users(a)nest-simulator.org
To unsubscribe send an email to users-leave(a)nest-simulator.org
--
Dr. Jochen Martin Eppler
Phone: +49(2461)61-96653
----------------------------------
Simulation Laboratory Neuroscience
Jülich Supercomputing Centre
Institute for Advanced Simulation
936
days inactive
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days old
8 comments
3 participants
participants (3)
-
Benedikt Feldotto -
Jochen Martin Eppler -
salvatore.taffara＠phd.unict.it