|Re: HP12C - Internal Rate of Return|
Message #3 Posted by Patrick on 8 Aug 2003, 2:32 p.m.,
in response to message #2 by Gene
In addition to what Gene has said, if any consecutive set of cash flows are equal, you can use the Nj function to specify how many times the flow repeats. Extending on Gene's example, suppose that there were flows in years 4, 5, and 6 that were all equal to the $3000 flow in year 3, then instead of keying these in individually, you can just type "4 g Nj" just before the "f IRR" keystrokes. The 4 signifies 4 payments of $3000 corresponding to the four years (3, 4, 5, 6).
Apart from saving some keystrokes, this method also saves on memory registers. Basically, you only use one memory slot for a repeated flow. Somehow, the HP engineers have stored the value of Nj (which can be as large as 99) in some spare bits inside the calculator, probably in the bits in the memory register which holds the payment itself.