The FIND command returns an empty matrix for a number I know exists

I am trying to find index of variable in a array. Its value is changing in a loop and corresponding to existing array e.g.

 z1 = zphoton(k,i)+(delz);

                index  = find(zpos ==round(z1*1000)/1000,1);
                    delz =delz+0.001

I know all values of z1 are in zpos but still I am getting empty matrix as index. Can someone please provide prompt response ?

Thanks AS

Answer 1

[Azzi Abdelmalek]

Look at http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F