HP calcs are really not that accurate..

[DA74254]

(12-01-2017 10:18 PM)Paul Dale Wrote:  What are you trying to represent that requires so many digits?
How can you possibly measure something that accurately?

256 digits are far more than you'd need to represent the diameter of the universe in terms of the planck length.


Pauli

I'm just nerdy.. I once made a "prime number finder" that took abt one hour to find 115 million primes (all primes below 4.294.967.295 as in unsigned long int)
And yes, I know exactly how big my land plot is in square plancks (just over 5,5x10^72)
So, for my opinion, the 256 was just arbitrary, based on the todays cpu capabilities.

(12-01-2017 10:37 PM)brickviking Wrote:  In addition, while computers have gobs of spare memory and awesome (!) floating point processors, calculators do not. Most calculators are not expected to be connected to the wall just to plain work (or charge their batteries after 9 hours of use), they're expected to work after 6 months (or more!) of use just the same as when the battery was first put in. This requires serious compromises in the choices of CPU or multifunction chip so as to make best use of the limited energy resources available from batteries.

As previously mentioned, the amount of precision you actually need is often very different from the amount of precision you want. It's also different from the amount of precision you can usefully create yourself due to tolerance factors. 5mm of tolerance in the amount of space required for a bridge would probably be acceptable given other environmental factors, however in the case of aeronautics, 5mm of tolerance on a flight from Auckland to Heathrow would be considered excessive, yet calculators can already give us that degree of precision (average of 10 dp, perhaps with 1-3 guard digits).

Let's not make this a "Schwanzvergleich" discussion.

(Post 138)

Regarding the power drain - my phone seems to cope with "massive precision", thoug, as I've learned from this discussion, that may be a lie..
And no, a "mine-is-bigger-than-yours" discussion was not my intension.

(12-02-2017 01:36 AM)Joe Horn Wrote:  Those who prefer to be lied to, so as to hear what they want to hear, should buy non-HP calculators, which fudge the displayed results to look like what they think that the user probably wants to see, with warts shaved off and blemishes hidden behind cosmetics (aka "guard digits").

Those who prefer to be told the truth, and see EXACTLY what the result is, warts and all, should buy HP calculators, whose philosophy is "What You See Is What You Have".

All calculators are inaccurate internally. Some just hide that fact by lying to the user, and they get away with it because many users (e.g. DA74254) prefer to be lied to. We HP aficionados prefer the truth.

Everybody is lied to every day and everybody hears what everybody thinks everybody wants to hear. So no, I do not want to be lied to any more than the next person.

Not wanting to step on any toes (which I accidentally did, apparently), I probably should approach this in my first post more like a question than a statement. I did learn something here, which is good. I also learned that the binary operation modus of electronics never can represent decimal output accurate (in short). (This last sentence probably don't sound correct, but English is not my native language).

(12-02-2017 01:59 AM)Luigi Vampa Wrote:  "Joe Horn dixit"
1+
I love your last post ;Ox

"It is the mark of an educated mind to rest satisfied with the degree
of precision which the nature of the subject admits, and not to seek
exactness where only an approximation is possible."
Aristotle

I should have listened to Aristotle..