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  #1  
Old 09-09-2012, 04:58 PM
victe victe is offline
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Default Question 10

From the results of running 1 vs 5, I met one of the possible answers, but it seems that is not correct. I can not say anything more for now... Maybe I made a mistake, but in the other questions related it seems I have the right answers.
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Old 09-10-2012, 05:46 AM
TonySuarez TonySuarez is offline
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Default Re: Question 10

My results also ended up pointing into only one of the hypothesis. But there can be some mistake in the code -- only 100% sure after submission . In fact, the results are not of the kind that would let yourself go into "relaxed" state .
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Old 09-12-2012, 11:59 AM
MLearning MLearning is offline
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Default Re: Question 10

The same here, simulation points to one of the answers. For some reason, I am not able to take comfort in that. I also did run my simulation for different values of lambda and they all seem to point to that same answer.
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Old 03-11-2013, 01:32 PM
jain.anand@tcs.com jain.anand@tcs.com is offline
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Default Re: Question 10

When i ran the simulation I am getting 2 answers that matches my result. Now I am really confused how to proceed. Can somebody help me which one I should select? I am getting these answers repeatedly. Is there some rule on how many iterations Gradient descent should be run? I see the gradient descent error keeps decreasing even after 2000 runs. It make no difference in the outcome though.
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Old 03-11-2013, 07:02 PM
hemphill hemphill is offline
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Default Re: Question 10

If the error keeps dropping, I would keep going. I didn't use gradient descent, myself. I solved it two ways, getting the same answer with both methods. First, I noted that it could be solved by quadratic programming. Second, I fed it to a (non-gradient) conjugate direction set routine that I've had lying around for years.
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Old 03-11-2013, 10:50 PM
tsweetser tsweetser is offline
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Default Re: Question 10

Is it also possible to use the regularized normal equation? I'm looking at Lecture 12, Slide 11.

It seems funny to me to choose the parameters to minimize one error measure (mean square), yet evaluate {E_in} and {E_out} using another (binary classification).
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  #7  
Old 03-11-2013, 11:07 PM
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yaser yaser is offline
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Default Re: Question 10

Quote:
Originally Posted by tsweetser View Post
Is it also possible to use the regularized normal equation? I'm looking at Lecture 12, Slide 11.
Yes, you can use any result given in the lectures.

Quote:
It seems funny to me to choose the parameters to minimize one error measure (mean square), yet evaluate {E_in} and {E_out} using another (binary classification).
Ideally, we would work exclusively with binary classification error in this case, but because of the intractability of optimization of that error, the mean-squared error is used for the optimization part.
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Old 03-12-2013, 09:40 AM
jain.anand@tcs.com jain.anand@tcs.com is offline
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Default Re: Question 10

Thank you professor, let me try the analytical solution approach and see if I get a different results. I am still getting 2 right answers from the quiz.
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Old 03-13-2013, 04:00 AM
SeanV SeanV is offline
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Default Re: Question 10

Regularised Linear regression is called ridge regression in the stats literature

you can just use whatever code you use to do linear least squares by adding dummy data( see data augmentation) in link below
http://www-stat.stanford.edu/~owen/c...larization.pdf

no need for quadratic programming / stoch descent etc
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Old 03-13-2013, 05:53 AM
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yaser yaser is offline
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Default Re: Question 10

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Originally Posted by SeanV View Post
Regularised Linear regression is called ridge regression in the stats literature

you can just use whatever code you use to do linear least squares by adding dummy data( see data augmentation) in link below
http://www-stat.stanford.edu/~owen/c...larization.pdf

no need for quadratic programming / stoch descent etc
Correct. The solution was also given in slide 11 of Lecture 12 (regularization).
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