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Building Recurrent Neural Networks in Tensorflow

Recurrent Neural Nets (RNN) detect features in sequential data (e.g. time-series data). Examples of applications which can be made using RNN’s are anomaly detection in time-series data, classification of ECG and EEG data, stock market predictionspeech recogniton, sentiment analysis, etc.

This is done by unrolling the data into N different copies of itself (if the data consists of N time-steps) .
In this way, the input data at the previous time steps t_n - 1, t_n - 2, t_n - 3, ... , t_0 can be used when the data at timestep t_n is evaluated. If the data at the previous time steps is somehow correlated to the data at the current time step, these correlations are remembered and otherwise they are forgotten.

By unrolling the data, the weights of the Neural Network are shared across all of the time steps, and the RNN can generalize beyond the example seen at the current timestep, and beyond sequences seen in the training set.

This is a very short description of how an RNN works. For people who want to know more, here is some more reading material to get you up to speed. For now, what I would like you to remember is that Recurrent Neural Networks can learn whether there are temporal dependencies in the sequential data, and if there are, which dependencies / features can be used to classify the data. A RNN therefore is ideal for the classification of time-series, signals and text documents.

So, Lets start with implementing RNN’s in Tensorflow and using them to classify signals.

To see the full blog-post click here.