#1




Failed to find the bias term for Q14
For Q15, I coded to find the K centers for the RBF. Then use pseudoinverse to find the . Then have difficulty to find the b. I think it should be calculated by picking any point, and substitute into the formula for x and y:
But, when I try it for all 100 points, all calculated b are different. Am I misunderstand something ? Or simply my program bug ? I read through all posts in the forum but cannot figure out any hints. Further, from "on the right track" post, I used the 4 points sample to test my code, I can find those centres and clusters and phi, but cannot match the weights. Without proper b, I cannot carry on the simulation for the remaining quiz. 
#2




Re: Failed to find the bias term for Q15
b should be found along with the other weight vectors  using pseudo inverse.
This will be similar to how we did in linear regression. Add a column in the phi matrix with all 1's  and if you solve for w, you will get b. 
#3




Re: Failed to find the bias term for Q15
Quote:
http://book.caltech.edu/bookforum/sh...40&postcount=7
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#4




Re: Failed to find the bias term for Q15
Thank you very much bargava and professor. Now I understand what is going on. Many thanks !

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