oddperiod.py

Created on November 16, 2021

545 Bytes

Payment on a monthly loan with an partial first period (0 to 59 days). The cash flow convention is used.

Source: HP 17BII+ Financial Calculator User’s Guide. Ed. 2. Hewlett Packard. San Diego, CA 2004

# 2021-11-14 EWS
# odd period

from math import *

print("Loan with partial period")
print("0 - 59 days")
print("Monthly Payments")
n=float(input("N: n? "))
rate=float(input("I/YR:  rate? "))
pv=float(input("PV: loan amt? "))
fv=float(input("FV: balooon pmt? "))
days=float(input("DAYS: odd period? "))

r=rate/1200

if days<30:
  j=1+r
else:
  j=1

f=days/30-int(days/30)
w=r*f+1
  
# uspv
u=(1-(1+r)**(-n))/r
# sppv
s=(1+r)**(-n)


pmt=(pv*w+fv*s)/(j*u)
# rounding
pmt=-int(pmt*100+.5)/100
# result
print("Payment: "+str(pmt))