(User.programs)
Item: 214 by _tasmith at hpcvbbs.UUCP
Author: [Ted A Smith]
  Subj: Uniform series of cash flows
  Keyw: cash flows, npv nfv nus irr
  Date: Wed Feb 06 1991

Here is a package to do uniform cash flow problems.

The equations used were gleaned from the HP18C manual and the output of this
package was checked against the 18C for some 'interesting' problems.  (But no
warrenty is made or implied (or something to that effect.))

The routines all operate on the data in \GSDAT and use XCOL and YCOL from
\GSPAR.  The XCOL column specifies the cash flows, the YCOL the number of
repeated flows which are the same value.  (By convention the initial flow has a
repetition of 1 (but nothing bad happens if this is not the case.))

The CST menu provides:

Total:     calculate Total of the cash flows with no interest.
I:         assigns interest (in units of percent per period)
<orange>I: calculate Internal Rate of Return (what I gives NPV==0)
<blue>I:   return current value of I
NPV:       calculate Net Present Value (what is loan worth now)
NPV:       calculate Net Uniform Series (equivalent equal paypments)
NFV:       calculate Net Future Value (what will loan be worth at end)

For example:
[[-50000  1]
 [  5000 12]
 [  6000  1]] '\GSDAT' STO

indicates that I make a loan of $50000.00, get twelve payments of $5000.00 and
a final payment of $6000.00.  If I can get a 6.25% return on my money per
period elsewhere, is this a good deal?  

Press 6.25 I NPV and you get -$5921.20; a bad loan.  How much would my return
on investment be?  Press <orange>I to calculate the internal rate of return and
you get 4.17%; not great.