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HP Forum Archive 16

 HP17BII+ - L() & G() RevisitedMessage #1 Posted by Peter A. Gebhardt on 17 Sept 2006, 11:56 a.m. To avoid such erroneous results like described here: After executing the steps described below, everything worked fine on my unit - S/N: CNA42903649 produced on a Monday !!! 2004 Week 29 ... 1. Initialize ALL first before you use L(:...) Example: INIT-L: 0*A*B* ... *Z=0 2. In SOLVER menu pres GOLD INPUT to CLEAR ALL VARIABLES! (WARNING - BE CAREFUL HERE! EXIT IMMEDIATELY, TO NOT TO DELETE YOUR STORED EQUATIONS by incidently pressing function key two as well!) 3. Multiply each instance of L(:...) by ZERO to avoid side-effects within your equation. Best regards, Peter A. Gebhardt Edited: 17 Sept 2006, 2:21 p.m.

 HP17BII+ - L() & G() Now working on HP49G+ !!!Message #2 Posted by Peter A. Gebhardt on 17 Sept 2006, 8:41 p.m.,in response to message #1 by Peter A. Gebhardt Because of the contribution of Tom Sears made on comp.sys.hp48 I finally was able to emulate L() & G() on my HP49G+ ... To test for yourself, take this example from Edition 2 of the HP17BII+ User Guide available here: On page 170 look for the description of L(x:expr): (1+i)^N x PV +((1–(1+i)^N)/(1–(1+i))) x PMT+FV It can be written as: L(NP:1+i) x 0 + L(NPN:G(NP)^N) x PV + ((1-G(NPN)) / (1-G(NP))) x PMT + FV On the HP49G+ change the last equation to: << 'NP x 0 + NPN x PV + ((1-NPN) / (1-NP)) x PMT + FV' {'NPN = NP^N' 'NP = 1 + i' } + << SUBST >> STREAM STEQ 30 MENU >> Quote:(18-Sep-2006, 9:48 GMT) Please be aware, that in { ... } order matters - "substitute" most complex first .... most simple last! (18-Sep-2006, 16:46 GMT) Please be also aware, that the example TVM equation listed in the HP17BII+ User Guide, doesn't work the same as the Financial Solver! If you encounter differences in i then it might be due to limits in the solver. Set initial values for i to .0001 before you solve for i. Look here under Problem 2. http://www.finseth.com/hpdata/timing.html In my opinion, it's comparably easy to identify the respective L() & G() parts of the HP17 equation and put them into the list to be worked on by SUBST & STREAM. Because I only tested with this readily available example, pls. comment once you have used the "algorithm" on your own HP17/19/200LX to HP49 migrations. Best regards, Peter A. Gebhardt Edited: 18 Sept 2006, 12:25 p.m.

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