Cruzada Categórica Entropia is a função de perda commonly usada em aprendizado de máquina, particularly in classification tasks where the goal is to predict one class out of multiple possible classes. It quantifies the difference between the predicted probability distribution produced by a model and the actual distribution of the classes observed in the data.
Em termos matemáticos, a Entropia Cruzada Categórica é definida como:
Loss = -Σ (yi * log(pi))
onde:
yiis the true distribution (one-hot encoded vector) of classes,piis the predicted probability of each class.
A função calcula a log-verossimilhança negativa of the true classes given the predicted probabilities. A lower value of categorical cross entropy indicates better performance of the model, as it means the predicted probabilities are closer to the actual labels.
This loss function is particularly useful in scenarios with multiple classes, such as classificação de imagens, where each sample belongs to one and only one class. Categorical Cross Entropy is often used in conjunction with softmax activation in neural networks, as it effectively handles the probabilities that sum to one across all classes.