measure distance between mutiple positions without looping

I have two arrays of XYZ positions data, Spots1 and Spots2. Code below loops though each Spot2 position and measures the distance to each Spots1 subtracted by radius of Spots2.

        for vIndex1= 1:size(Spots2,1)
            vDist(:,vIndex1) = (sqrt((Spots1(:,1)-Spots2(vIndex1,1)).^2 + (Spots1(:,2)-Spots2(vIndex1,2)).^2))-Radius2(vIndex1);
        end
        vLimit=min(vDist,[],2);% find minimum value for each row for each dendrite position
        vIsClose(vSpotsIndex1) = vLimit < vDistanceLimit;

I am looking for a way to do this without the for loop. My ultimate goal is to find minimum distance measure for each Spots1 position. And if it is less than a set value, to create an array of those spot positions.

There are similar answers, but nothing exactly what i am looking for. Any help would be appreciated. Thank you.

Answer 1

[Star Strider]

If you have the Statistics Toolbox, the pdist2 function will find the distances.

EDIT — If you don’t have the Stats Toolbox, a loop is the only way to go. You can make your code a bit more efficient with the hypot function.

Answer 2

[Image Analyst]

If you have the stats toolbox, try pdist().

[Matthew]

I am planning on getting that toolbox, for myself, but I would like to have a way to do it without it. Is it possible?