how to define Sorenson distance as a function

[poster]

I wrote this function for computing Sorenson distance (the formula of Sorenson is attached), Is this code right?

function [ fsnd ] = fSorensonDist( p,q )

    a=abs(p-q);

    b=p+q;

    s=0;

    as=0;

    bs=0;

    for i=1:size(p,1)

    as=as+a(i);

    bs=bs+b(i);

     if as~=0 && bs~=0

         s=(as/bs);

     end

    end

    fsnd=s;

    end

the colon is 62*2001 dataset, when I use this function in my program instead of 62 instances I found 2 instances(rows) in the output.

  clc;

  clear;

  close all;

  load colon.mat 

  data=colon; 

  [n,m]=size(data);

  for i=1:m-1

      for j=i+1:m

            t(i,j)=fChebyshevDist(data(:,i),data(:,j));

              b=sum(t)/(m-1);

     end

    end

I'll be very grateful to have your opinions. Thanks

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