I am getting this preallocation warning
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Jan
2022년 11월 19일
@Vânia Gonçalves: A general hint is to search in the net at first. Asking an internet search engine for "Matlab preallocate" shows useful explanations already.
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Steven Lord
2022년 11월 19일
This is a Code Analyzer warning not a run-time warning.
If you're not sure what preallocation is, why it can be important, or how to do it see the first example on this documentation page.
Jan
2022년 11월 19일
이동: Jan
2022년 11월 19일
Seriously? If I ask Google, I get e.g.:
- https://www.mathworks.com/help/matlab/matlab_prog/preallocating-arrays.html
- https://www.mathworks.com/matlabcentral/answers/99124-how-do-i-pre-allocate-memory-when-using-matlab
For your code:
...
maxIter = 1000;
x = zeros(maxIter, 1);
y = zeros(maxIter, 1);
while norm(J) > e && i < maxIter
...
end
x = x(1:i); % Crop unused elements
y = y(1:i);
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Jan
2022년 11월 19일
What does "long" mean? Seconds or hours?
Symbolic calculations need some time. You can use the profiler to find the bottleneck:
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