Values closest to a number

How do I find the two closest numbers from a number in a vector column? For example, suppose I have:

A = [2 3 5 6 9 10 23 45 100]';

If the number I'm seaching is 7, my requested answer would be 6 and 9.

[bym]

why wouldn't it return 5 & 6? 5 is as close as 9

Answer 1

[Wayne King]

It looks like you are looking for the closest numbers where one is below 7 and one is above. If that is the case.

    A = [2 3 5 6 9 10 23 45 100]';
    num = 7;
    closest_below = max(A(A<num));
    closest_above = min(A(A>num));

because otherwise, 5 is just as close to 7 as 9 is.

[cfjunior]

Yes, thats what I need!! Thanks a lot!!

Answer 2

[the cyclist]

There are many possible ways to do this. Here is one way.

A = [2 3 5 6 9 10 23 45 100]';

v = 7;

idx_hi = find(A>7,1,'first');

twoClosest = A([idx_hi-1,idx_hi])

I assumed that your A vector was sorted, that all values are unique, etc. You want to be careful if these conditions are not met.