Retropropagação
Backpropagation, short for ‘backward propagation of errors’, is a fundamental algorithm used for training artificial redes neurais. It enables the network to learn from the errors it makes during the prediction process, thereby improving its accuracy ao longo do tempo.
O processo começa com uma passagem direta, onde os dados de entrada são alimentados na rede neural, and predictions are made. After obtaining the output, the algorithm calculates the error by comparing the predicted output to the actual target values. This error is crucial because it indicates how far off the predictions are from the desired outcomes.
Next, backpropagation works by propagating this error backward through the network. It uses the chain rule of calculus to compute the gradient of the função de perda with respect to each weight in the network. This involves determining how much each weight contributed to the output error. By calculating these gradients, backpropagation identifies which weights need to be adjusted and by how much.
Os ajustes são feitos usando uma algoritmo de otimização, such as Stochastic Gradient Descent (SGD), which updates the weights in the direction that minimizes the error. This iterative process continues over many cycles (or epochs), allowing the neural network to learn from the data and improve its predictions with each iteration.
Backpropagation is essential for training deep learning models, as it efficiently handles the complex computations required for multi-layer networks. Its ability to minimize loss through gradient descent is what makes it a powerful tool in the campo de inteligência artificial e aprendizado de máquina.