Compares the fractions @a_n/@a_d and @b_n/@b_d and returns -1 if a < b, 0 if a = b and 1 if a > b.
Numerator of first value
Denominator of first value
Numerator of second value
Denominator of second value
Return: -1 if a < b; 0 if a = b; 1 if a > b.
See Implementation
Compares the fractions @a_n/@a_d and @b_n/@b_d and returns -1 if a < b, 0 if a = b and 1 if a > b.