java 엑셀 함수 NPV 구현

public static double npv(double[] arrVal, double r){

double npvVal = 0;

for(int i=0;i<arrVal.length;i++){

npvVal += (arrVal[i]/Math.pow(1+r, i));

}

System.out.println("NPV : " + npvVal);

return npvVal;

}