HP17bii+ solver question

[Don Shepherd]

This is frustrating.

Can anyone tell me why I get "Solution not found" when I enter a value for N and solve for SOD (sum of digits):

sod=0xL(A:LOG(N)+1)+sigma(I:1:A:1:MOD(N:10)+0xL(N:IP(N/10)))

[Gerson W. Barbosa]

It works on both the HP-200LX and HP-17BII. It seems there is (or there was) a problem with L() and G() on the HP-17BII+ :

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv016.cgi?read=91896

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv014.cgi?read=67528

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv014.cgi?read=64409

Gerson.

[Don Shepherd]

Thanks Gerson.

Yes, I had noticed some of those threads before, and I guess I just hoped that the problems were fixed by now. I should have known better. You know, the beauty of computers and programming is (supposed to be) that they work the same way every time, with consistency, and according to their documentation. In my 33 years of programming on IBM, Univac, and DEC mainframes, that has been true. The only two cases where it was not true was with HP calculators; the original 12cp with 400 program steps that you could use only if you had no GTO's, and now the 17bii+. When a hobby is just frustrating, it's not a hobby anymore.

I am returning to my 16c and my Martin guitar.

[bill platt]

When HP calculators become KinHPo calculators, sadly the attention to detail and quality simply evaporated.

Buying a real 17bii is your only real option.

[Gerson W. Barbosa]

Quote:

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the beauty of computers and programming is (supposed to be) that they work the same way every time, with consistency, and according to their documentation.

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That's quite true!

Quote:

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The only two cases where it was not true was with HP calculators; the original 12cp with 400 program steps that you could use only if you had no GTO's, and now the 17bii+.

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At least that 12CP bug has been solved. If you want another example of lack of consistency between the 200LX and the HP-17BII solvers, consider this equation:

COS=0*L(X:(-1)^(L(Q:IP(ABS(L(X:MOD((90-X):360)))/90))+

FACT(G(Q)))*((180*(G(Q)-IP(G(Q)/2)))-X))+L(Y:SIGMA(N:0:5:1:

(-1)^N*(X*PI/540)^(2*N+1)/FACT(2*N+1)))*(3-4*SQ(G(Y)))

The HP-200LX has no trouble solving for X, given COS. However, the HP-17BII returns the complement of the expected answer. It started working only when +0*L(X:90-X) was appended to the equation. This kind of thing is really frustrating.

Regards,

Gerson.

Edited: 24 Feb 2007, 11:58 a.m.

[Chris]

why did the framers made