code: private static RadialBasisFunction[] rep(RadialBasisFunction rbf, int k) {
          RadialBasisFunction[] arr = new RadialBasisFunction[k];
          Arrays.fill(arr, rbf);
          return arr;
      }
docs: Returns an array of radial basis functions initialized with given values.
  @param rbf the initial value of array.
  @param k the size of array.
  @return an array of radial basis functions initialized with given values