Noisy results from Neural Network

5 次查看（过去 30 天）

Sam136 2014-8-10

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/147095-noisy-results-from-neural-network

编辑： Sam136 2014-8-21

I've trained a feed-forward neural network with 4 inputs and 2 targets with 10000 sample data. When I use this network for testing on a set of data, the average of data seems acceptable, but it is very noisy (see attached figure). Any suggestion to resolve this issue? I have tried many different layer and neuron numbers, as well as training methods, but no major improvement.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Greg Heath 2014-8-10

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/147095-noisy-results-from-neural-network#answer_148101

在 MATLAB Online 中打开

Try preprocessing with a lowpass filter.

The cheapest one I can think of is

x(i) = mean([x0(i-1),x0(i),x0(i+1)]) % 3-point moving average

I don't necessarily recommend it, it is just an example. Better to find a good LPF reference.

Hope this helps.

Thank you for formally accepting my answer

Greg

8 个评论
显示 6更早的评论隐藏 6更早的评论

Greg Heath 2014-8-19

Sorry, my response assumed the input data was one-dimensional.

I think you can better understand your results if you do the following for each input

[sortx1 ind1] = sort(input(1,:));

figure, hold on plot(sortx1,target(ind1),'k--') plot(sortx1,output(ind1),'b')

Hope this helps,

Greg

Greg Heath 2014-8-19

It doesn't appear to me that the output is significantly more noisy than the target.

Maybe you can see it better with other plotting options or plotting error (target-output).

请先登录，再进行评论。

更多回答（1 个）

Sam136 2014-8-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/147095-noisy-results-from-neural-network#answer_149285

编辑：Sam136 2014-8-20

I changed my net to dynamic(narxnet) with zero delay for input and 1:2 delay for feedback, but I still have the problem. Below figures show NN response to the input data (same data that I used for training the network).

2 个评论
显示无隐藏无

Greg Heath 2014-8-20

在 MATLAB Online 中打开

If you are going to switch to narxnet. See my posts on how to choose delays

greg nncorr

how to choose number of hidden nodes

greg Hub

and how to normalize results

 greg NMSE
 greg R2
 greg R2a

Sam136 2014-8-21

编辑：Sam136 2014-8-21

Thanks Greg. The network worked, and the results are pretty good. I have a question though. I have a difficulty to use the trained network (narxnet) for new set of input data. I get dimension error and it seems that I should include the target values. However, there is no target values when we want to use the network. Can you help me in this regard?

请先登录，再进行评论。

请先登录，再回答此问题。