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-   -   Minimizing Ein by differentiation wr.t w (http://book.caltech.edu/bookforum/showthread.php?t=4447)

 blunderboy 10-17-2013 10:22 PM

Minimizing Ein by differentiation wr.t w

https://dl.dropboxusercontent.com/u/...ection_008.png

Can somebody please explain me how we got X' (X' is X Transpose) outside the braces after differentiation. Shouldn't it be X instead of X'.

When I revisited the lecture, I recalled professor saying it is not actually square. It is just transpose multipled by itself. This concept is not clear to me..

Appreciate the help :)

 yaser 10-18-2013 12:34 AM

Re: Minimizing Ein by differentiation wr.t w

Quote:
 Originally Posted by blunderboy (Post 11580) https://dl.dropboxusercontent.com/u/...ection_008.png Can somebody please explain me how we got X' (X' is X Transpose) outside the braces after differentiation. Shouldn't it be X instead of X'. When I revisited the lecture, I recalled professor saying it is not actually square. It is just transpose multipled by itself. This concept is not clear to me.. Appreciate the help :)
This comes from matrix calculus. The quantity is in fact .

The squared matrix I referred to was .

 blunderboy 10-18-2013 05:45 AM

Re: Minimizing Ein by differentiation wr.t w

Aah..Got it. Thank you professor. I really appreciate the quick help from you. Your presence in the forum really help us. Thanks a lot!!:D

 yaser 10-18-2013 11:46 AM

Re: Minimizing Ein by differentiation wr.t w

Quote:
 Originally Posted by blunderboy (Post 11583) Aah..Got it. Thank you professor. I really appreciate the quick help from you. Your presence in the forum really help us. Thanks a lot!!:D
You are most welcome.

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