How to find X value of given Y close to zero ?

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Terence
Terence 2020-12-9
评论： Terence 2020-12-10
Hello!
My question is How to find the value of Y more close to zero first (note Y consists of both positive and negative numbers) and then find the corresponding X value from a matrix ? Many thanks in advance.
For example: 6x6 matrix
338.00 339.00 340.00 341.00 342.00 343.00
1.00 -100.00 -100.00 -100.00 -100.00 -100.00 -100.00
2.00 100.00 100.00 100.00 100.00 100.00 100.00
3.00 0.28 0.12 -0.05 -0.21 -0.38 -0.55
4.00 0.28 0.12 -0.05 -0.21 -0.38 -0.55
5.00 8.21 8.24 8.26 8.28 8.30 8.32
6.00 8.21 8.24 8.26 8.28 8.30 8.32
To find the value closest to 0, which is -0.05 corresonding to the value 340. 340 is the output value.

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采纳的回答

dpb
dpb 2020-12-9
[~,ix]=min(abs(m),[],'all','linear');
[~,j]=ind2sub(size(m),ix);
>> o(j)
ans =
340
>>

更多回答（1 个）

Jon
Jon 2020-12-9
编辑：Jon 2020-12-9
Here's another approach that is maybe more obvious to understand
x = [338.00 339.00 340.00 341.00 342.00 343.00]
data = [ ...
-100.00 -100.00 -100.00 -100.00 -100.00 -100.00
100.00 100.00 100.00 100.00 100.00 100.00
0.28 0.12 -0.05 -0.21 -0.38 -0.55
0.28 0.12 -0.05 -0.21 -0.38 -0.55
8.21 8.24 8.26 8.28 8.30 8.32
8.21 8.24 8.26 8.28 8.30 8.32]
% find column locations of minimum
[~,icol] = min(abs(data)) % columns correspond to x values
% select the x value corresponding to the column where the minimum was found
% just need the first instance if there are more than one
xmin = x(icol(1))
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dpb
dpb 2020-12-10
Glad to help...teaching as well as "just" answers is the goal of many of us here...
Terence
Terence 2020-12-10
Glad to see my question raised discussion! Thanks for helping! Merry Xmas!

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