如何编写ArrayFieldVector的子类 <Complex> （Apache Commons）

Question

There are ArrayFieldVector class in ApacheCommons:

    public class ArrayFieldVector<T extends FieldElement<T>> implements FieldVector<T>, Serializable

Now I need to work with complex vectors.

    ArrayFieldVector<Complex> c = new ArrayFieldVector<>(100, new Complex(1,0));

The problem is that there aren't pow method in ArrayFieldVector class. So I decided to write my own class:

  public class ComplexVector extends ArrayFieldVector<Complex>{
    Complex[] data=super.getDataRef();

    public ComplexVector(Complex[] c){
       super(c);
    }

    public ComplexVector pow(double p){
       Complex[] out=new Complex[data.length];
       for(int i=0;i<data.length;i++){
           out[i]=data[i].pow(p);
                                     }
       return new ComplexVector(out);
  }
}

Now I can pow ComplexVector but can not add ComplexVector to ArrayFieldVector because there are no add method with ComplexVector argument. One of the solution is to rewrite all this metods (add, multiply, ebeAdd,...) with ComplexVector argument. Maybe there are other way to solve this problem?

Answer 1

You'd better use something like this:

public final class ArrayFieldVectorUtils {

    private ArrayFieldVectorUtils(){
        // avoid instantiation
    }

    public static ArrayFieldVector<Complex> pow(final ArrayFieldVector<Complex> a, int pow){
       Complex[] out = new Complex[a.length];
       for(int i=0;i<a.length;i++){
           out[i]=a[i].pow(pow);
                                     }
       return new ArrayFieldVector<Complex>(out);
    }
}

Usage: ArrayFieldVectorUtils.pow(someArrayFieldVector, 3)