# Machine Learning Meetup Notes Ruby Zhao 2

```class ML
@@weights_for_binary = [0, 0, 0]
@@weights_for_linear = [0.0]

def weights_for_binary
@@weights_for_binary
end

def weights_for_linear
@@weights_for_linear
end

def binary_training_set
[[[1, 0, 0], 1], [[1, 0, 1], 1], [[1, 1, 0], 1], [[1, 1, 1], 0]]
end

def linear_training_set
[[[1.0], 2.0], [[1.5], 3.0], [[2.0], 4.0]]
end

def threshold
0.5
end

def dot_product(input, weights)
[input, weights].transpose.map{ |e| e = e[0] * e[1] }.inject{ |s, n| s += n }
end

def binary_train_all
train_all(binary_training_set, weights_for_binary, lambda{ |a,b| dot_product(a, b) > threshold ? 1 : 0 })
end

def linear_train_all
train_all(linear_training_set, weights_for_linear, lambda{ |a,b| dot_product(a, b) })
end

def sigmoid_train_all

end

def stop_condition(training_set, counter, repetition, weights)
counter == training_set.size || ( repetition > 1500 && rms(weights) < 0.01)
end

def rms(w)
Math.sqrt(w.inject(0){ |s, n| s += n * n } / w.size)
end

def train_all(training_set, weights, activation_function)
counter = 0
repetition = 0
learning_rate = 0.9
while !stop_condition(training_set, counter, repetition, weights)
counter = 0
repetition += 1
training_set.each do |set|
counter += train(set[0], set[1], learning_rate, weights, activation_function)
end
learning_rate *= 0.99
p learning_rate
puts "intermediary weights: " + weights.join(":")
end
puts "final weights: " + weights.join(":")
end

def train(input, expected_output, learning_rate, weights, activation_function)
actual_output = activation_function.call(input, weights)
train_step = (expected_output - actual_output) * learning_rate
return 1 if train_step == 0

input.each_with_index do |inp, index|
weights[index] += inp * train_step
end

0
end
end
```