small bug in financial calculator

[Terry]

Documentation on the Financial Calculator is in order before using it I guess.
There is documentation in the CVS, I think, I sent it to Dave mixed in with the
source and I would guess that he stuck it in there - look for finutil.html.

As I read what you entered, there is no solution for interest. 

You entered:
12 periodic payments,
present Value = 15,000
periodic payments = 400, and
future value = 0.

You deposited/invested/whatever 15,000 and continue to deposit/invest/whatever
400 per payment. After 12 payments you have a value of 15,000 + 12*400 = 19,800,
with no interest paid at all. But you have entered 0 for the value after the 12
payments, you have in essence said that you consider 19,800 == 0 . Thus, no
solultion, an illogical situation.  Change the +400 to -400 and you will get a
solution, i = -171.39%. Is that what you really wanted? That is you receive 400
per periodic payment and the other side of the deal is subtracting interest
from your original deposit/investment/whatever at the rate of 171.39% annually
so that you get back 12*400 == 4800 from your original 15,000. Good deal for
the other side. They collect interest of 10,200 for the transaction

Now, having said that, the s/w should probably be smart enough to protect you
from such situations. I will see if it is possible to think of all such
possibilities and put in place a sanity check function.

Thanks for the input.

On Sun, 10 Dec 2000, you wrote:
> Hi,
> 
> you can cause the financial calculator (and gnucash) to hang as follows:
> 
> Payments periods
> 12
> 
> Interest Rate
> ??
> 
> Present Value
> 15000
> 
> Periodic Payments
> +400  (!!!!?)
> 
> Future Value
> 0
> 
> Once you entered these values, press calculate in Interest rate's field. 
> Then gnucash will hang. (gnucash 5.2, status Saturday 12/9/2000)
> 
> One question: did I post the bug at the right place or is there a more 
> appropriate place to do it?
> 
> Thanks
> 
> Mauro
> 
> 
> _____________________________________________________________________________________
> Get more from the Web.  FREE MSN Explorer download : http://explorer.msn.com
> 
> 
> _______________________________________________
> gnucash-devel mailing list
> gnucash-devel@lists.gnumatic.com
> http://www.gnumatic.com/cgi-bin/mailman/listinfo/gnucash-devel