How to choose value from array based on closest value

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!

Answer 1

[Walter Roberson]

If the values in the first column are sorted, use interp1() with 'nearest'

[Alex]

This worked perfectly, thanks!

Answer 2

[Ruchika P Barman]

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