Re: The "Karl's solver"  HELP VPN Message #24 Posted by bill platt (les Estats Unis d'Amerique) on 13 May 2004, 6:34 p.m., in response to message #23 by VeliPekka Nousiainen
Hi VeliPekka,
OK, here's the deal: You have to tell the machine which variable is going to be solved for, before running solve. You do this by STOring the register address in to <I> before calling f<solve> <address> (It is exactly backwards of the 32sii model, where you 1st tell the machine which function is to be solved, and then when you press solve, the machine asks for the variable to be solved for).
You also must tell the machine what the declared variables values are first, before you do the f<solve> <address> call
[quote] from Karl: Use the I register in a general program. For example, to solve or integrate a function with variables x, y, and z:
(x) STO 1; (y) STO 2; (z) STO 3 {here you are storing the delcared values to the appropriate registersthis can happen before or after you make the programhere it is shown before}
001 LBL "A" {in program mode, make an program address}
002 STO (i) {this is the command which makes it all work}
(use RCL 1, RCL 2, and RCL 3 each time a variable is used)
nnn RTN
Key in n STO I (n = 1,2 or 3) and STO each of the parameters (fixed variables) as above prior to executing SOLVE or INTEGRATE on the program "A".
Any numbered registers may be used; the 15C won't use your choices for its own purposes.
That having been said, the 32Sii and 42S *are* much faster numbercrunchers. While the 32Sii allows equations to be solved and integrated, RPN programs run faster.
[/quote]
OK, so like S=1/2at^2 + vi*t goes like this:
make 1/2at^2+vi*t S = 0
t STO 1
a STO 2
vi STO 3
S STO 4
LBL A
STO i
RCL 1
<ENTER>
<ENTER>
<ENTER> {Horner's method.....not really needed entirely}
RCL 2
*
2
/
RCL 3
+
*
RCL 4

RTN
So to solve for S, start by storing all the acceleration, time intitial velocity etc, then 4 STO I, then f<solve><A>
of course you can also store an initial guess in register 4 and etc.
To solve for another variable, just STO its register address in (I) and proceed with f<solve>A
I don't have my 15c in front of me but it should work.
Have fun!
Best regards,
Bill
Edited: 13 May 2004, 6:53 p.m.
