Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.matlab

Topic: Error in Selection of Optimum Parameters in Neural Network
Replies: 3   Last Post: Apr 18, 2013 10:08 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Subodh Paudel

Posts: 2
Registered: 4/17/13
Error in Selection of Optimum Parameters in Neural Network
Posted: Apr 17, 2013 7:00 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hello All,
I have an error in selection of optimum configuration from the neural network model. I consist R2 statisticics for training, R2 statistics for training under degree of freedom adjustment and i choose the highest (R2 statistics for training under degree of freedom adjustment + R2 for Validation:).

Which is the best condition here:
Case Neurons R2Train R2Train-DOF R2Val R2Tst MSETrain MSEval R2Train-DOF+R2Val
1 9 0.8901 0.8832 0.8799 0.751 0.109 0.119 1.7632
2 16 0.8906 0.8777 0.8871 0.785 0.109 0.111 1.7646
3 19 0.9005 0.8864 0.8641 0.768 0.099 0.1347 1.7505


In three case, which one is the best?
1) In my understanding, case 2 shows better results since R2 statics for training under biased i.e. degree of freedom adjustment plus R2 for validation is greater than rest case. But there is also contradiction that R2val (0.8871) is greater than R2 training under biased condition (0.8777), which should not exist. So, my optimum choice is case 1 which does not violate any rule.

Please, any one could suggest me. Further, as Prof. Greg Heath mentioned about Degree of Freedom adustment for (Hmax and Training equation... Hub=-1+ceil((Ntrneq-O)/(I+O+1));
Hmax=round(Hub/8);), why this is done to avoid overfitting problems or what?
Please, could you send the references so that i could site this equation for the conference paper which i am sending?

Thank you in advance.

Subodh



Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.