I used the bidirectional LSTM and I would like to save its training accuracy. According totrainingoptions, 'OutputFcn' is output functions to call during training, specified as the comma-separated pair consisting of 'OutputFcn' and a function handle or cell array of function handles. trainNetwork calls the specified functions once before the start of training, after each iteration, and once after training has finished. trainNetwork passes a structure containing information in certain fields. One of them is TrainingAccuracy. How can I accomplish my goal to save training accuracy of my trained network?