Multi-format calculator - Software Development Case Studies in Java - page 133

public class Rational {
static final double PRECISION # 10;
static final double EPSILON # Math.pow(10,-PRECISION);
double numerator # 0.0;
double denominator # 1.0;
public Rational( double num, double den) {
numerator # num;
denominator # den;
simplify();
}
public Rational( double number) {
numerator # number;
denominator # 1.0;
canonical();
simplify();
}
The constructors make use of two methods: canonical() and simplify() . The
former ensures that numerator and denominator are both integers, with an
approximation of ten decimal figures. The latter simplifies the fraction by
dividing both numerator and denominator by their common divisors.
void canonical() {
double num # Math.abs(numerator);
double decimal # num - Math.floor(num);
int num_digits # 0;
while (decimal > EPSILON && num_digits < PRECISION) {
num # num * 10;
decimal # num - Math.floor(num);
num_digits !! ;
}
numerator # numerator * Math.pow(10.0, num_digits);
denominator # denominator * Math.pow(10.0, num_digits);
}
public void simplify() {
double divisor # Math.min(Math.abs(numerator),
denominator);
for (; divisor > 1.0; divisor - # 1.0) {
double rn # Math.abs(Math.IEEEremainder(
Math.abs(numerator), divisor));
double rd # Math.abs(Math.IEEEremainder
(denominator, divisor));
if (rn < EPSILON && rd < EPSILON) {
numerator / # divisor;
denominator / # divisor;
divisor # Math.min(Math.abs(numerator),
denominator);
}
}
}