Lab4 Loan Payment

void setup() {
  size(685, 500);
  background(0);
  fill(255);
  monthly_loan_payment(5000, 12, 1);
}
void monthly_loan_payment(float loan_amount, float interest_rate, int loan_term) {
  float ratepermonth = (interest_rate/100)/12;
  float paypermonth = loan_amount*(ratepermonth/(1-pow(1+ratepermonth, -(loan_term*12))));//M=P*(J/(1-(1+J)^-n))
  float unpaid = loan_amount;
  float total_interest = 0;
  int month = 1;
  textSize(25);
  text("Monthly Loan Payment", 205, 30);
  textSize(17);
  text("Payment No.        Interest        Principal        Unpaid Balance        Total Interest", 20, 70);
  int Y =110;
  while (month <= (loan_term*12)) {
    float interest = ratepermonth*unpaid;
    total_interest+=interest;
    float principal = paypermonth-interest;
    unpaid = abs(unpaid-principal);
    text(nf(month, 2), 60, Y);
    text("$"+nf(interest, 1, 2), 168, Y);
    text("$"+nf(principal, 1, 2), 272, Y);
    text("$"+nf(unpaid, 1, 2), 408, Y);
    text("$"+nf(total_interest, 3, 2), 576, Y);
    Y+=30;
    month++;
  }
}