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HP Forum Archive 21

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SCIOVR and ENGOVR in FIX mode
Message #1 Posted by Andrew Nikitin on 1 July 2013, 3:00 p.m.

I think the way WP34s switches from FIX mode to SCI or ENG on overflow and underflow is not quite right.

For example, FIX 04 shows exactly 4 digits after decimal point. As the number grows bigger, it keeps showing 4 digits after decimal, but all digits before decimal. As number keeps growing and there is no more room for digits after decimal, they are getting dropped: first 3 digits are shown, then 2, then 1. All this time it shows all digits before decimal -- so far so good. Then suddenly it switches to sci or eng and shows only 5 digits. It think this is wrong, at least no other calculator does it. At overflow it should switch to unrestricted eng or sci -- just the way ALL mode does. The numeric parameter of FIX should apply to the FIX-specific behavior, not to fallback behaviour.

Another glitch is what happens at underflow: in, say, FIX 02 numbers less that 1e_3 are shown in SCI 02 or ENG 02. I think this is incorrect. It should show 0.00 or -0.00. Or just 0.00, if -0.00 is too much trouble. When people select FIX, it is to not see smaller fractions of 10, whether because they do not care, or because it does not make sense, like dollars and cents.

At least, this is traditional interpretation of FIX mode by other calculators.

      
Re: SCIOVR and ENGOVR in FIX mode
Message #2 Posted by Marcus von Cube, Germany on 1 July 2013, 3:33 p.m.,
in response to message #1 by Andrew Nikitin

Quote:
It think this is wrong, at least no other calculator does it. At overflow it should switch to unrestricted eng or sci -- just the way ALL mode does.
I've just checked my 15C in FIX 4 mode. It shows 4 digits after the decimal point and all digits left to it as long as the number fits the display. When the number gets too large, the 15C switches to SCI 4 mode, showing exactly 5 digits. This is what WP 34S does in SCIOVR mode.
      
Re: SCIOVR and ENGOVR in FIX mode
Message #3 Posted by Paul Dale on 1 July 2013, 4:51 p.m.,
in response to message #1 by Andrew Nikitin

Marcus is correct, I followed the behaviour of preexisting HP calculators in the display code.

- Pauli

            
Re: SCIOVR and ENGOVR in FIX mode
Message #4 Posted by Andrew Nikitin on 1 July 2013, 10:21 p.m.,
in response to message #3 by Paul Dale

Hm. Just checked with the few hps i have, and you are right. Does not mean that this is correct interpretation, but, I guess, I am in minority here.

Just think about it. You are looking national debt in FIX 02. When it under a trillion you see every dollar. But when it is even slightly above you just suddenly see only first three digits of it -- like billion here, billion there -- who cares?

                  
Re: SCIOVR and ENGOVR in FIX mode
Message #5 Posted by Walter B on 2 July 2013, 1:10 a.m.,
in response to message #4 by Andrew Nikitin

Quote:
You are looking national debt in FIX 02. When it under a trillion you see every dollar. But when it is even slightly above you just suddenly see only first three digits of it -- like billion here, billion there -- who cares?
Modeling the behaviour of the real world quite truely, doesn't it?

d;-)

                  
Re: SCIOVR and ENGOVR in FIX mode
Message #6 Posted by Victor Koechli on 2 July 2013, 4:46 a.m.,
in response to message #4 by Andrew Nikitin

Quote:
Just think about it. You are looking national debt in FIX 02. When it under a trillion you see every dollar. But when it is even slightly above you just suddenly see only first three digits of it -- like billion here, billion there -- who cares?
You had me laughing out loud for at least a minute! Thanks for this! Regards, Victor


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