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Old 10-14-2012, 05:43 AM
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magdon magdon is offline
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Default Re: About the Problem 3.17b

Yes, in this problem you can use (u,v)=(0,0) from part (a).

||(∆u,∆v)||=0.5 means that the step size \eta=0.5.

In the chapter we considered two step sizes. First where the step size was fixed at \eta. Second where the step size is proportional to the norm of the gradient. Here, for part (b) the step size is fixed at 0.5.

Originally Posted by rpistu View Post
Yes, E1 is a function of ∆u, ∆v, but it is also a function of u, v. Then, what is the u, v in this function? Still use (0, 0) as part (a) said? Also, what is the ininital value of ∆u, ∆v? In the textbook, it sets w to w(0) at step 0.

Further, does the norm ||(∆u,∆v)||=0.5 means that for each iteration we should ensure that the values of ∆u,∆v meet this resuirements? Another point is that in textbook, we need specify the step size ɧ. However, we could not see any information about the step size.

I don't quite understand the description of the question (Problem 3.17b), so I have so many questions. Could you probably clarify it for me?
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