tvm.py

Created on December 13, 2021

997 Bytes

TVM Solver: Time Value of Money Solver. Solves for PMT, FV, PV, or N. Run tvm() or press the var button and select tvm(). Select the variable to solve for, and the inputs are similar to the TI calculators.

from math import *
def tvm():
  print("Select variable to solve:")
  print("1:PMT 2:FV 3:PV 4:N")
  solv=int(input("?"))
  
  if solv != 4:
    N=int(input("  N= "))
    
  r=float(input(" I%= "))
  
  if solv != 3:
    pv=float(input(" PV= "))
  
  if solv != 1:
    pmt=float(input("PMT= "))
  
  if solv != 2:
    fv=float(input(" FV= "))
  
  ppy=int(input("P/Y= "))
  
  if r > 1:
    r=r/100
    
  if solv == 1:
    pmt=-r/ppy*(fv+pv*(1+r/ppy)**N)/((1+r/ppy)**N-1)
    print("")
    print("Periodic Payment:")
    print("pmt=",pmt)
    
  if solv == 2:
    fv=(ppy*pmt-ppy*pmt*(1+r/ppy)**N-pv*r*(1+r/ppy)**N)/r
    print("")
    print("Future Value:")
    print("FV=",fv)
    
  if solv == 3:
    pv=((1+r/ppy)**(-N)*(ppy*pmt-fv*r-ppy*pmt*(1+r/ppy)**N)/r)
    print("")
    print("Present Value:")
    print("PV=",pv)
    
  if solv == 4:
      N=log((ppy*pmt-fv*r)/(ppy*pmt+pv*r))/log(1+r/ppy)
      print("")
      print("Number of Payments:")
      print("N=",N)