PT21-22-Reseau-Neurones/sobek/network.py

126 lines
5.6 KiB
Python
Executable File

import numpy as np
import math
class network:
def __init__(self, inputLayerSize, *layerSizes):
if type(inputLayerSize) != int:
raise TypeError("The input layer size must be an int!")
self.__weights = []
self.__inputLayerSize = inputLayerSize
oldLayerSize = inputLayerSize
for layerSize in layerSizes:
self.__weights.append( np.random.random((layerSize, oldLayerSize)) )
oldLayerSize = layerSize
self.__biases = [[0]*layerSize for layerSize in layerSizes]
self.__weights = np.array(self.__weights, dtype=object)
self.__biases = np.array(self.__biases, dtype=object)
def __reLu(value, derivative=False):
if (derivative):
return 0 if (value == 0) else 1
return max(0, value)
def __sigmoid(value, derivative=False):
if (derivative):
return network.__sigmoid(value) * (1 - network.__sigmoid(value))
return 1/(1+math.exp(-value))
def process(self, _input, __storeValues=False):
if type(_input) != np.ndarray:
raise TypeError("The input must be a vector!")
if _input.size != self.__inputLayerSize:
raise ValueError("The input vector has the wrong size!")
#if _input.dtype != np.float64:
# raise TypeError("The input vector must contain floats!")
if (__storeValues):
self.activations = []
self.outputs = []
for layerWeights, bias in zip(self.__weights, self.__biases):
_input = np.matmul(layerWeights, _input)
_input = np.add(_input, bias)
if (__storeValues):
self.activations.append(_input.copy())
#activation function application
for neuron in range(len(_input)):
_input[neuron] = network.__sigmoid(_input[neuron])
#On peut comparer la performance si on recalcul plus tard
if (__storeValues):
self.outputs.append(_input.copy())
self.activations = np.array(self.activations, dtype=object)
self.outputs = np.array(self.outputs, dtype=object)
return _input
def train(self, inputs, desiredOutputs, learningRate):
errorSumsWeights = [[[0]*len(neuron) for neuron in layer] for layer in self.__weights]
errorSumsBiases = [[0]*len(layer) for layer in self.__biases]
self.__errors = [[0]*len(layer) for layer in self.__weights]
for _input, desiredOutput in zip(inputs, desiredOutputs):
#rempli self.activations et self.outputs
self.__output = self.process(_input, True)
self.__desiredOutput = desiredOutput
#Somme de matrice ?
for layerNumber in range(len(errorSumsWeights)-1, -1, -1):
for neuronNumber in range(len(errorSumsWeights[layerNumber])):
errorSumsBiases[layerNumber][neuronNumber] += self.__Error(layerNumber, neuronNumber)
for weightNumber in range(len(errorSumsWeights[layerNumber][neuronNumber])):
#print("layer : " + str(layerNumber) + " neuron : " + str(neuronNumber) + " weight : " + str(weightNumber))
errorSumsWeights[layerNumber][neuronNumber][weightNumber] += self.__PartialDerivative(layerNumber, neuronNumber, weightNumber)
total = 0
errorSumsWeights = np.multiply(errorSumsWeights, -(learningRate/len(inputs)))
self.__weights = np.add(self.__weights, errorSumsWeights)
errorSumsBiases = np.multiply(errorSumsBiases, -(learningRate/len(inputs)))
self.__biases = np.add(self.__biases, errorSumsBiases)
print(self.__biases)
"""
for layerNumber in range(len(errorSumsWeights)):
for neuronNumber in range(len(errorSumsWeights[layerNumber])):
for weightNumber in range(len(errorSumsWeights[layerNumber][neuronNumber])):
#Probablement faisable avec une multiplication de matrices
errorSumsWeights[layerNumber][neuronNumber][weightNumber] = errorSumsWeights[layerNumber][neuronNumber][weightNumber] / len(inputs)
total += errorSumsWeights[layerNumber][neuronNumber][weightNumber]
#Probablement faisable avec une somme de matrices
self.__weights[layerNumber][neuronNumber][weightNumber] -= learningRate * errorSumsWeights[layerNumber][neuronNumber][weightNumber]
print("Error : " + str(total))"""
def __Error(self, layer, neuron):
if (self.__errors[layer][neuron] == 0 ):
self.__errors[layer][neuron] = self.__ErrorFinalLayer(neuron) if (layer == len(self.__weights)-1) else self.__ErrorHiddenLayer(layer, neuron)
return self.__errors[layer][neuron]
def __ErrorFinalLayer(self, neuron):
return network.__sigmoid(self.activations[len(self.activations)-1][neuron], True) * (self.__output[neuron] - self.__desiredOutput[neuron])
def __ErrorHiddenLayer(self, layer, neuron):
upperLayerLinksSum = 0
#Probablement faisable avec une multiplication de matrices
for upperLayerNeuron in range(len(self.__weights[layer+1])):
upperLayerLinksSum += self.__weights[layer+1][upperLayerNeuron][neuron] * self.__errors[layer+1][upperLayerNeuron]
return network.__sigmoid(self.activations[layer][neuron], True) * upperLayerLinksSum
def __PartialDerivative(self, layer, neuron, weight):
return self.__Error(layer, neuron) * self.outputs[layer-1][weight]