def train(self, input_array, target_array):
#converts the input array to a vector
inputs = Matrix.array_to_vector(input_array)
hidden = Matrix.dot_product(self.weight_iput_to_hidden, inputs)
hidden.add(self.bias_of_hidden)
hidden.map(NeuralNetwork.sigmoid)
output = Matrix.dot_product(self.weight_hidden_to_output, hidden)
output.add(self.bias_of_output)
output.map(NeuralNetwork.sigmoid)
target_Matrix = Matrix.array_to_vector(target_array)
#calculate error
error = Matrix.sub(target_Matrix, output)
self.error = error
weight_hidden_to_output_t = Matrix.transpose(
self.weight_hidden_to_output)
hidden_error = Matrix.dot_product(weight_hidden_to_output_t, error)
#calculate the gradient of the hidden layer
hidden_gradient_matrix = Matrix.map_s(output, NeuralNetwork.d_sigmoid)
hidden_gradient_matrix.scale(error)
hidden_gradient_matrix.scale(self.lr)
delta_weights_ho = Matrix.dot_product(output, Matrix.transpose(hidden))
#update weights and biases
self.weight_hidden_to_output.add(delta_weights_ho)
self.bias_of_output.add(hidden_gradient_matrix)
#calculate the gradient of the output layer
output_gradient_matrix = Matrix.map_s(hidden, NeuralNetwork.d_sigmoid)
output_gradient_matrix.scale(hidden_error)
output_gradient_matrix.scale(self.lr)
delta_weights_ih = Matrix.dot_product(hidden, Matrix.transpose(inputs))
#update weights and biases
self.bias_of_hidden.add(output_gradient_matrix)
self.weight_iput_to_hidden.add(delta_weights_ih)
def predict(self, input_array):
inputs = Matrix.array_to_vector(input_array)
hidden = Matrix.dot_product(self.weight_iput_to_hidden, inputs)
hidden.add(self.bias_of_hidden)
hidden.map(NeuralNetwork.sigmoid)
output = Matrix.dot_product(self.weight_hidden_to_output, hidden)
output.add(self.bias_of_output)
output.map(NeuralNetwork.sigmoid)
return output.to_array()
def __init__(self,
no_of_input,
no_of_hidden,
no_of_output,
weight_file="weights.txt"):
user_cancel = False
if (weight_file == ""):
user_cancel = True
self.num_of_input_nurons = no_of_input
self.num_of_hiddden_nurons = no_of_hidden
self.num_of_output_nurons = no_of_output
#check if exist the weights of the local drive
isWeightsExist = Path(weight_file).exists()
if (isWeightsExist and not user_cancel):
f = open(weight_file, "r")
f1 = f.readlines()
w = []
w_count = 0
b = []
b_count = 0
w_i_h = []
w_h_o = []
b_h = []
b_o = []
for text in f1:
if (text.find("w")) != -1:
w.append(ast.literal_eval(text.split(":")[1]))
elif (text.find("b")) != -1:
b.append(ast.literal_eval(text.split(":")[1]))
for i in range(no_of_hidden):
w_i_h.append([])
for j in range(no_of_input):
w_i_h[i].append(w[w_count])
w_count = w_count + 1
for i in range(no_of_hidden):
b_h.append([])
for j in range(1):
b_h[i] = b[b_count]
b_count = b_count + 1
for i in range(no_of_output):
w_h_o.append([])
for j in range(no_of_hidden):
w_h_o[i].append(w[w_count])
w_count = w_count + 1
for i in range(no_of_output):
b_o.append([])
for j in range(1):
b_o[i] = b[b_count]
b_count = b_count + 1
self.weight_iput_to_hidden = Matrix.array_to_matrix(
w_i_h, no_of_hidden, no_of_input)
self.weight_hidden_to_output = Matrix.array_to_matrix(
w_h_o, no_of_output, no_of_hidden)
self.bias_of_hidden = Matrix.array_to_vector(b_h)
self.bias_of_output = Matrix.array_to_vector(b_o)
else:
self.weight_iput_to_hidden = Matrix(no_of_hidden, no_of_input)
self.weight_hidden_to_output = Matrix(no_of_output, no_of_hidden)
self.weight_iput_to_hidden.randomize()
self.weight_hidden_to_output.randomize()
self.bias_of_hidden = Matrix(no_of_hidden, 1)
self.bias_of_output = Matrix(no_of_output, 1)
self.bias_of_hidden.randomize()
self.bias_of_output.randomize()
