BP神经网络实现测试数据预测(将训练集与测试集数据进行归一化 建立BP神经网络，并训练；利用训练好的BP神经网络对测试集中的23个样本的抗压强度进行预测；输出结果并绘图)-BP neural network to predict the test data (the training set and test data set is normalized　the BP neural network and training　use of the trained BP neural network on the compressive strength of 23 samples in the test set prediction　output results and drawing)