/**
* Multiplies the two polynomials together.
*
* @param a Polynomial
* @param b Polynomial
* @param result Optional storage parameter for the results. Must be have enough coefficients to
* store the results. If null a new instance is declared.
* @return Results of the multiplication
*/
public static Polynomial multiply(Polynomial a, Polynomial b, Polynomial result) {
int N = Math.max(0, a.size() + b.size() - 1);
if (result == null) {
result = new Polynomial(N);
} else {
if (result.size < N) throw new IllegalArgumentException("Unexpected length of 'result'");
result.zero();
}
for (int i = 0; i < a.size; i++) {
double coef = a.c[i];
int index = i;
for (int j = 0; j < b.size; j++) {
result.c[index++] += coef * b.c[j];
}
}
return result;
}
