# How to find the closest value of a given number in a table?

The Situation is as follows:

I have to arrays, symbolizing a positive domain `x`, and another array whose a function of that domain `z`

Now, I want, for a given point `y`, to find the `z` value in the nearest location. For thatI wrote the following function:

``````R0 = @(y) z(find(abs( abs(y). -  r) == min(abs(abs(y). - r))))
```
```

(The use of `abs` is for negative values of `y`, since `z` is symmetric)

This works perfectally well, unless `y` is a vector. So, if I use the following code:

``````y = [-1:0.01:1];
R0(y);
```
```

I get the following error:

``````Error using  ==
Matrix dimensions must agree.
```
```

Trying to debug it, I came to see that the `find` statement returned a 1*0 matrix, hence nothing. This is although the value of `y` ACTUALLY EXSIST in the `r` array.

What I really want is to get a new vector, which assign the nearest value in `z` for each value of `y`.

Other, totally different solutions might be used, so I prefer understanding why this solution doesn't work and how can I make it work.

Thanks

Your question is not very clear. If I understand correctly, for each element of `y` you want to find the closest element in `z`.

``````y = [1 2 3 4 5]; %// example data
z = [0 2.5 6]; %// example data
d = abs(bsxfun(@minus, y(:).', z(:))); %'// compute distance for all pairs
[~, ind] = min(d); %// index of minimizer in z for each value of y
result = z(ind);
```
```

In this example,

``````result =
0    2.5000    2.5000    2.5000    6.0000
```
```