for and while loop
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Hi
I am looking to run a while loop that solves a rootfinding problem for two initail values, stored in a matrix as described below. It should store the two solved coordiantes in xysolve.
The while loop works fine when running with ii = 1 or ii = 2 (indexing the two initial values) independtly.
However it does not work within the for loop, that I want to use to run the rootfinding for both initail values, one after the other.
Not sure what is the problem here.
Many thanks in advance for any help.
T
%% Solving
% Initial estimates are 2 2x1 vectors: [-10; 10] and [10;-10]
% These are stored together in 2x2 matrix xy
xy = [-10 10 ; 10 10];
iter = 0; imax=100; tol=0.001; err=tol;
xysolve = zeros(2,2)
for ii = 1:2
while iter <= imax && err >= tol
iter = iter + 1;
xy_new = xy(:,ii) - Jacob(xy(:,ii))\f(xy(:,ii));
err = norm(f(xy(:,ii)));
xy = [0 0 ; 0 0]
xy(:,ii) = xy(:,ii) + xy_new
xysolve = xy
end
end
3 个评论
Bob Thompson
2021-1-21
'However it does not work within the for loop'
What does this mean? What exactly isn't working? Are you getting an error, or what about your results is telling you that it isn't working?
T
2021-1-21
T
2021-1-21
采纳的回答
Rik
2021-1-21
0 个投票
You need to reset the error term and iteration count at the start of the for loop. Otherwise it will keep the previous values and immediately exit the while loop.
3 个评论
Rik
2021-1-21
You are wiping your initial value array as well by setting xy=zeros(2);. But otherwise, yes, this is what I meant.
As a further note: I would strongly suggest using the automatic indentation for readability. I would also suggest adding comments about what the code is doing.
T
2021-1-21
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