Find Command and Empty matrix: 1-by-0 Error

I know there is a value but find command generate error. Now sure how to fix!

x_matrix=[0:0.1:0.9] [a]=find(x_matrix==0.3)

results a =

   Empty matrix: 1-by-0

Answer 1

[Andrei Bobrov]

a = find(abs(x_matrix - 0.3) < 100*eps)

please read this is