public Quaternionf add(double x, double y, double z, double w) {
        return add((float) x, (float) y, (float) z, (float) w);
    }
public Quaternionf add(double x, double y, double z, double w) {
        return add((float) x, (float) y, (float) z, (float) w);
    }
public Quaternionf add ( double x , double y , double z , double w ) { return add ( ( float ) x , ( float ) y , ( float ) z , ( float ) w ) ; }
Adds the double components of another quaternion to this one.

@param x The x (imaginary) component of the quaternion to add
@param y The y (imaginary) component of the quaternion to add
@param z The z (imaginary) component of the quaternion to add
@param w The w (real) component of the quaternion to add
@return A new quaternion, which is the sum of both
Adds the double components of another quaternion to this one .