Thread: About the Problem 3.17b View Single Post
#3
10-13-2012, 08:17 PM
 rpistu Member Join Date: Oct 2012 Posts: 10
Re: About the Problem 3.17b

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?

Quote:
 Originally Posted by magdon is a function of . You want to choose math]\Delta u,\Delta v[/math] (the vector to move in) to minimize . The negative gradient direction is going to be the direction to move (this is shown in the chapter) and you have to rescale that so the step size is 0.5.