Pretty much. If you want to compare two floats a and b within some precision eps, use:

    abs(a - b) <= eps*0.5*(a + b)

or even

    (abs(a - b) <= eps*abs(a)) && (abs(a - b) <= eps*abs(b))

which is implemented in Boost [0].

[0] http://www.boost.org/doc/libs/1_34_0/libs/test/doc/component...