Hi. Some few notes about what I think is happening. The break inside the for loop stops the for loop, not the while one. So, you must put it there. Thus, the tolerance checking must be in the while loop too, and to do that you have the vectorial function normi(x) or max(vectorize(abs(x))) for comparing with only one TOL. Finally, you need to increase the counter i outside the for loop.

BTW, looking at the Error array, it looks like there is an issue at row 2.

While Loop Not Working.sm (16kb) downloaded 9 time(s).

Best regards.
Alvaro.

Edited by user 20 December 2023 18:25:33(UTC)  | Reason: Not specified

For a general numerical procedure to minimize or find roots the guess initial value is part of the problem start data, not a result of some reasoning, except that you study the behavior of some particular function.

For example for solving f(x) = 0, f(x) = 1 - x^2 starting with x = 0.5 you usually get x = 1, and with x = -0.5 results x = -1. That means that you must know something about the solution before starting a numerical procedure.

In your case your m independent variable is not scalar, but vectorial. You can't add m+0.01 ... you must add 0.01 for each component looking to all combinations, which actually could be done, but is a kind of brute force method. Usually you know something about the desired result and use that to select "good" guess values for each component.



Not stopping just because of an issue with m[2]. The Error for other components decreases very quickly. Just check if it needs a different guess value or why with the values of the others variables it not converges to a solution.

Best regards.
Alvaro.

I finally got it working :-) I had to break out my pencil and notepad and go through the first couple of iterations manually. Attached is the loop that works.

While Loop with Vectors.sm (19kb) downloaded 8 time(s).