Problem while developing a multivariate Regression model using neural network

Dear all,
I am trying to develop a multivariate regression model to predict some variable x which is a function of inputs such as, universal time (UT), latitude, longitude etc. I have used a feedforward network with one input layer, one hidden layer (40 neurons) and an output layer. I have used tansig as the activation function. I have completed the training and currently testing the network. I am facing a problem with the network.
At the boundaries of the UT, the values predicted by the model are not matching. I could see a clear 'jump' between 23.75 UT and 0UT. But, my data doesn't have any jump. I have checked with different data sets having the diurnal variation and I am facing the same issue. Why did the model fail to predict the values at the boundaries?
I didn't understand this problem clearly. Is the periodicity (means data repeat every 24 hours) of data causing the issue?
Kindly help in this regards.
Thanks in advance.

4 个评论

Why can't you just unwrap UT to get a linear variable?
Greg
I can't do that because the data has the variation with the time (UT). All the variables that I have mentioned earlier have a significant influence on the output. The current NN training has captured the variation with UT except at the boundaries.
like greg said you should convert the UT into linear time and transform the data accordingly and also i think you should normalize all the variables in case you have not.
@ Greg and @Nikhil
I have already normalized the data.
By the way, how to convert the UT into liner time? Could you please elaborate?

请先登录,再进行评论。

回答(0 个)

类别

帮助中心File Exchange 中查找有关 Deep Learning Toolbox 的更多信息

产品

版本

R2017b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by