LSTM broken output

What is wrong?

Running a value against the network gives some strange outputs

Where does it happen?

In brain.recurrent.LSTM on my Surface, latest version of Windows, x64

How do we replicate the issue?

1. Run this code in brain.js:

const brain = require('brain.js');
const net = new brain.recurrent.LSTM();

const trainingData = [
  {
    input: 'Hello',
    output: 'Hi'
  },
  {
    input: 'Hi',
    output: 'Hello'
  },
  {
    input: 'Greetings!',
    output: 'Hello'
  },
  {
    input: 'Hello',
    output: 'Greetings!'
  },
  {
    input: 'Hi, How is it going?',
    output: 'Good'
  },
  {
    input: 'Hi, How is it going?',
    output: 'Fine'
  },
  {
    input: 'Hi, How is it going?',
    output: 'Okay'
  },
  {
    input: 'Hi, How is it going?',
    output: 'Great'
  },
  {
    input: 'Hi, How is it going?',
    output: 'Could be better.'
  },
  {
    input: 'Hi, How is it going?',
    output: 'Not so great.'
  }
];

net.train(trainingData, {
  log: true,
  logPeriod: 100,
  learningRate: 0.3,
  iterations: 2000
});

const output = net.run('hi');
console.log(output);

How important is this (1-5)?

5

Expected behavior (i.e. solution)

I should have gotten this response (or something simillar): "Hello"

Other Comments

Instead of “Hello”, I got NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

[robertleeplummerjr]

👍 Looking into this now, fyi.

[raphtlw]

The only fix I found for it is to create a set of key-value pairs like this:

{
  input: 'Hi, How is it going?',
  output: '0'
}

Where 0 corresponds to “Great” after getting the output of the network.