dot method
Inner product.
Implementation
double dot(Vector4 other) {
final Float64List otherStorage = other._v4storage;
double sum;
sum = _v4storage[0] * otherStorage[0];
sum += _v4storage[1] * otherStorage[1];
sum += _v4storage[2] * otherStorage[2];
sum += _v4storage[3] * otherStorage[3];
return sum;
}