If you are trying to train your own Neural Network, please use this code. Here in this example, the code reads the EMNIST dataset and convert the dataset as variables, suitable for nprtool. It is supposed that you already have download the EMNIST Dataset from Kaggle and keep it in same directory where this code is present. After running this code two variables, named as 'targetsd' and 'inputs' make sure you save them as .mat file