Metadata-Version: 2.1
Name: sorn
Version: 0.3.2
Summary: Self-Organizing Recurrent Neural Networks
Home-page: https://github.com/Saran-nns/sorn
Author: Saranraj Nambusubramaniyan
Author-email: saran_nns@hotmail.com
License: OSI Approved :: MIT License
Keywords: Brain-Inspired Computing,Artificial Neural Networks,Neuro Informatics,Spiking Cortical Networks,Neural Connectomics,Neuroscience,Artificial General Intelligence,Neural Information Processing
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: Topic :: Scientific/Engineering :: Artificial Intelligence
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Description-Content-Type: text/markdown
Requires-Dist: numpy
Requires-Dist: configparser
Requires-Dist: tqdm
Requires-Dist: scipy
Requires-Dist: seaborn

## Self-Organizing Recurrent Neural Networks 

SORN is a class of neuro-inspired artificial network build based on plasticity mechanisms in biological brain and mimic neocortical circuits ability of learning and adaptation through neuroplasticity mechanisms.

The network is developed as part of my Master thesis at UniversitÃ¤t OsnabrÃ¼ck, Germany. For the ease of maintainance, the notebooks, use cases and the API(under developement) are moved to https://github.com/Saran-nns/PySORN_0.1 

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<h4 align="Left">SORN Reservoir and the evolution of synaptic efficacies</h4>
<a href="url"><img src="https://raw.githubusercontent.com/Saran-nns/PySORN_0.1/master/v0.1.0/doc/images/SORN1.png" height="320" width="430"></a> <a href="url"><img src="https://raw.githubusercontent.com/Saran-nns/PySORN_0.1/master/v0.1.0/doc/images/weights.png" height="375" width="425" ></a> <a href="url"><img src="https://raw.githubusercontent.com/Saran-nns/PySORN_0.1/master/v0.1.0/doc/images/networkxx.jpg" height="375" width="425" ></a>

### To install the latest release:

```python
pip install sorn
```

The library is still in alpha stage, so you may also want to install the latest version from the development branch:

```python
pip install git+https://github.com/Saran-nns/sorn
```

### Dependencies
SORN supports Python 3.5+ ONLY. For older Python versions please use the official Python client


### Usage:

#### Update Network configurations
There are two ways to update/configure the network parameters,
1. Navigate to home/conda/envs/ENVNAME/Lib/site-packages/sorn
 ```or``` if you are unsure about the directory of ```sorn```

Run

```python
import sorn

sorn.__file__
```
to find the location of the sorn package

Then, update/edit arguments in ```configuration.ini```

2. Pass the arguments with valid names (listed below). This will override the default values at ```configuration.ini```
. The allowed ```kwargs``` are,
```Python
kwargs_ = ['ne', 'nu', 'network_type_ee', 'network_type_ei', 'network_type_ie', 'lambda_ee','lambda_ei', 'lambda_ie', 'eta_stdp','eta_inhib', 'eta_ip', 'te_max', 'ti_max', 'ti_min', 'te_min', 'mu_ip','sigma_ip']
```
#### Simulation: Plasticity Phase
The default ```ne, nu``` values are overriden by passing them as kwargs inside```simulate_sorn``` method.

```Python
# Import 
from sorn import Simulator

# Sample input 
num_features = 10
time_steps = 200
inputs = np.random.rand(num_features,timesteps)

# To simulate the network; 
matrices_dict, Exc_activity, Inh_activity, Rec_activity, num_active_connections = Simulator.simulate_sorn(inputs = inputs, phase='Plasticity', matrices=None, noise = True, time_steps=time_steps, ne = 200, nu=num_features)

# To resume the simulation, load the matrices_dict from previous simulation;
matrices_dict, Exc_activity, Inh_activity, Rec_activity, num_active_connections = Simulator.simulate_sorn(inputs = inputs, phase='Plasticity', matrices=matrices_dict, noise= True, time_steps=time_steps,ne = 200, nu=num_features)
```

#### Training phase:

```Python
from sorn import Trainer
inputs = np.random.rand(num_features,1) 

# SORN network is frozen during training phase
matrices_dict, Exc_activity, Inh_activity, Rec_activity, num_active_connections = Trainer.train_sorn(inputs = inputs, phase='Training', matrices=matrices_dict,nu=num_features, time_steps=1)
```

### Network Output Descriptions:
  ```matrices_dict```  - Dictionary of connection weights ('Wee','Wei','Wie') , Excitatory network activity ('X'), Inhibitory network activities('Y'), Threshold values ('Te','Ti')

  ```Exc_activity``` - Collection of Excitatory network activity of entire simulation period

  ```Inh_activity``` - Collection of Inhibitory network activity of entire simulation period

  ```Rec_activity``` - Collection of Recurrent network activity of entire simulation period

  ```num_active_connections``` - List of number of active connections in the Excitatory pool at each time step 


### Sample use with OpenAI gym :
#### Cartpole balance problem
Without changing the default network parameters. 

```python
# Imports

from sorn import Simulator, Trainer
import gym

# Load the simulated network matrices
# Note these matrices are obtained after the network achieved convergence under random inputs and noise

with open('simulation_matrices.pkl','rb') as f:  
    sim_matrices,excit_states,inhib_states,recur_states,num_reservoir_conn = pickle.load(f)

# Training parameters

NUM_EPISODES = 2e6
NUM_PLASTICITY_EPISODES = 20000

env = gym.make('CartPole-v0')

for EPISODE in range(NUM_EPISODES):

    # Environment observation
    state = env.reset()[None,:]

    # Play the episode
    while True:
      if EPISODE < NUM_PLASTICITY_EPISODE:

        # Plasticity phase
        sim_matrices,excit_states,inhib_states,recur_states,num_reservoir_conn = Simulator.simulate_sorn(inputs = state, phase ='Plasticity', matrices = sim_matrices, noise=False)

      else:
        # Training phase with frozen reservoir connectivity
        sim_matrices,excit_states,inhib_states,recur_states,num_reservoir_conn = Trainer.train_sorn(inputs = state, phase = 'Training', matrices = sim_matrices, noise= False)

      # Feed excit_states as input states to your RL algorithm, below goes for simple policy gradient algorithm
      # Sample policy w.r.t excitatory states and take action in the environment

      probs = policy(np.asarray(excit_states),output_layer_weights))
      action = np.random.choice(action_space,probs)
      state,reward,done,_ = env.step(action) 

      if done:
        break
```

### Sample Plotting functions 

```Python
from sorn import Plotter
# Plot weight distribution in the network
Plotter.weight_distribution(weights= matrices_dict['Wee'], bin_size = 5, savefig = False)

# Plot Spike train of all neurons in the network
Plotter.scatter_plot(spike_train = np.asarray(Exc_activity), savefig=False)


Plotter.raster_plot(spike_train = np.asarray(Exc_activity), savefig=False)
```

### Sample Statistical analysis functions

```Python
from sorn import Statistics
#t-lagged auto correlation between neural activity
Statistics.autocorr(firing_rates = [1,1,5,6,3,7],t= 2)

# Fano factor: To verify poissonian process in spike generation of neuron 10
Statistics.fanofactor(spike_train= np.asarray(Exc_activity),neuron = 10,window_size = 10)
```

### The network is inspired by following articles:

Lazar, A. (2009). SORN: a Self-organizing Recurrent Neural Network. Frontiers in Computational Neuroscience, 3. https://doi.org/10.3389/neuro.10.023.2009

Hartmann, C., Lazar, A., Nessler, B., & Triesch, J. (2015). Whereâ€™s the Noise? Key Features of Spontaneous Activity and Neural Variability Arise through Learning in a Deterministic Network. PLoS Computational Biology, 11(12). https://doi.org/10.1371/journal.pcbi.1004640 

Del Papa, B., Priesemann, V., & Triesch, J. (2017). Criticality meets learning: Criticality signatures in a self-organizing recurrent neural network. PLoS ONE, 12(5). https://doi.org/10.1371/journal.pone.0178683 

Zheng, P., Dimitrakakis, C., & Triesch, J. (2013). Network Self-Organization Explains the Statistics and Dynamics of Synaptic Connection Strengths in Cortex. PLoS Computational Biology, 9(1). https://doi.org/10.1371/journal.pcbi.1002848  



