Coursera吴恩达机器学习编程作业(ex4)包含BackPropagation算法的NeuralNetwork多层分类
nnCostFunction.mfunction[Jgrad]=nnCostFunction(nn_params,input_layer_size,hidden_layer_size,num_labels,X,y,lambda)%NNCOSTFUNCTIONImplementstheneuralnetworkcostfunctionforatwolayer%neuralnetworkwhichpe