NaN%在NARX net MATLAB中？

我使用带有外部输入的非线性自回归网络（NARX）来训练和测试我的数据。但我在计算MAPE时得到了NAN%。错误和实际数据在最后一行显示NAN%，如所示：

现在，我正在经过培训的网络

net

Test inputs=17544x8
Test inputs=17544x1

我正在使用延迟

% Create a Nonlinear Autoregressive Network with External Input
inputDelays = 1:1;
feedbackDelays = 1:1;
hiddenLayerSize = 10;
net = narxnet(inputDelays,feedbackDelays,hiddenLayerSize);

% Create a Nonlinear Autoregressive Network with External Input
inputDelays = 1:1;
feedbackDelays = 1:1;
hiddenLayerSize = 10;
net = narxnet(inputDelays,feedbackDelays,hiddenLayerSize);