# How to choose value from array based on closest value

6 views (last 30 days)
Alex on 13 Jul 2022
Answered: Ruchika P Barman on 13 Jul 2022
I have a 41x2 array. I want to take an input variable, find the closest value in the first column, and assign the corresponding value in the second column to a new variable.
Any pointers on how I would go about doing this?
For example:
1. Input value is x = 3.2
2. Search first column in array for 3.2
3. Closest value is 3
4. Value in 2nd column corresponding to 3 is 500
5. Store 500 to new variable y
Thanks!

Walter Roberson on 13 Jul 2022
If the values in the first column are sorted, use interp1() with 'nearest'
Alex on 13 Jul 2022
This worked perfectly, thanks!

Ruchika P Barman on 13 Jul 2022
It is my understanding that you are trying to get the element closest to the input number by comparing with all the elements in the matrix column-wise. The following code should be able to achieve the same.
V=[0.87]
V = 0.8700
arr = rand(41,2)
arr = 41×2
0.0928 0.4712 0.5737 0.6716 0.0275 0.0357 0.3457 0.5579 0.6198 0.3686 0.1062 0.9167 0.5590 0.4408 0.1859 0.6384 0.8755 0.7567 0.3914 0.0726
for c=1:2
N=arr(:,c);
A = repmat(N,[1 length(V)]);
[minValue,closestIndex] = min(abs(A-V'));
closestValue = N(closestIndex);
V=closestValue;
end
V
V = 0.8895

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