nwbext-simulation-output 0.1

Extension for storing large-scale simulation output in the Neurodata Without Borders: Neurophysiology format

# nwbext_simulation_output: An extension for output data of large-scale simulations
Developed in collaboration between the Soltesz lab and the Allen Institute during [NWB Hackathon #4](https://github.com/NeurodataWithoutBorders/nwb_hackathons/tree/master/HCK04_2018_Seattle/Projects/NetworkOutput) by Ben Dichter*, Kael Dai*, Aaron Milstein, Yazan Billeh, Andrew Tritt, Jean-Christophe Fillion-Robin, Anton Akhipov, Oliver Ruebel, Nicholas Cain, Kristofer Bouchard, and Ivan Soltesz

This extension defines a single NWB data type, `CompartmentSeries`, that allows you to store continuous data (e.g. membrane potential) from many compartments of many cells in a scalable way.


This structure stores an arbitrarily large number of cells and cellular compartments with 5 datasets. It can scale to a million or more neurons, and enables efficient parallel read and write. It is designed to handle NEURON output data and to easily interface with the SONATA format.

## Guide
### python
#### installation
```
pip install git+https://github.com/bendichter/simulation_output.git
```

#### usage
```python
from pynwb import NWBHDF5IO, NWBFile
from datetime import datetime
from nwbext_simulation_output import CompartmentSeries, Compartments
import numpy as np


compartments = Compartments()
compartments.add_row(number=[0, 1, 2, 3, 4], position=[0.1, 0.2, 0.3, 0.4, 0.5])
compartments.add_row(number=[0], position=[np.nan])
cs = CompartmentSeries('membrane_potential', np.random.randn(10, 6),
compartments=compartments,
unit='V', rate=100.)
nwbfile = NWBFile('description', 'id', datetime.now().astimezone())
nwbfile.add_acquisition(compartments)
nwbfile.add_acquisition(cs)

with NWBHDF5IO('test_compartment_series.nwb', 'w') as io:
io.write(nwbfile)
```

### MATLAB
#### installation

command line:
```
git clone https://github.com/bendichter/nwbext_simulation_output.git
```

in matlab:
```matlab
generateExtension('/path/to/nwbext_simulation_output/nwbext_simulation_output/nwbext_simulation_output.namespace.yaml');
```

#### usage
```matlab
[number, number_index] = util.create_indexed_column( ...
{[0, 1, 2, 3, 4], 0}, '/acquisition/compartments/number');

[position, position_index] = util.create_indexed_column( ...
{[0.1, 0.2, 0.3, 0.4, 0.5], 0}, '/acquisition/compartments/position');

compartments = types.simulation_output.Compartments( ...
'colnames', {'number', 'position'}, ...
'description', 'membrane potential from various compartments', ...
'id', types.core.ElementIdentifiers('data', int64(0:5)));

compartments.position = position;
compartments.position_index = position_index;
compartments.number = number;
compartments.number_index = number_index;

membrane_potential = types.simulation_output.CompartmentSeries( ...
'data', randn(10,6), ...
'compartments', types.untyped.SoftLink('/acquisition/compartments'), ...
'data_unit', 'V', ...
'starting_time_rate', 100., ...
'starting_time', 0.0);

nwb.acquisition.set('compartments', compartments);
nwb.acquisition.set('membrane_potential', membrane_potential);
```

## Talks
Ben Dichter*, Kael Dai*, Aaron Milstein, Yazan Billeh, Andrew Tritt, Jean-Christophe Fillion-Robin, Anton Akhipov, Oliver Ruebel, Nicholas Cain, Kristofer Bouchard, Ivan Soltesz. NWB extension for storing results of large-scale neural network simulations. NeuroInformatics. Montreal, Canada (2018). [video](https://www.youtube.com/watch?v=uuYQW0EE2GY).