How Accurate is Accurate Enough?
04-11-2021, 07:26 PM
Post: #7
 toml_12953 Senior Member Posts: 1,915 Joined: Dec 2013
RE: How Accurate is Accurate Enough?
(04-11-2021 01:15 PM)Chumango Wrote:  When my HP-41CV refused to turn on any more, my search for a fix or replacement led me to several places, one of them being this forum. A topic I have seen is "the most accurate calculator" or other similar themes, with 10, 12, 14, or even more digits accuracy. It makes me ask, how accurate is accurate enough?

I have worked my entire career as a chemical engineer with that 41CV I got used in 1983. I have never had a situation where its ten digits did not provide orders of magnitude better accuracy than would be meaningful. It is rare that I ever do a calculation that has more than 4 digits for all the inputs, so my calculator is always far more accurate than is needed.

Are there real-life calculations where 10, 12, 14 digits are actually required? Or is it a matter of getting more digits and accuracy because we can? Just curious.

As a side note, my searches revealed a simple way to address my 41CV, and it is working again. But that did not stop me from falling into the rabbit hole - now I also have a 35S and a DM41X.

I worked on guided missiles with nothing more FORTRAN double precision numbers (about 16 digits) My involvement with the missile program came to an end when I goofed and forgot a comma changing a line of code like this

DO 100 I=1,500

to this

DO 100 I=1 500

according to FORTRAN, the second line assigns 1500 to the variable DO100I instead of looping and incrementing the variable I 500 times. Both statements are perfectly legal in FORTRAN IV which ignores imbedded spaces.

The missile had to be aborted. The brass weren't amused.

Tom L
Cui bono?
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 Messages In This Thread How Accurate is Accurate Enough? - Chumango - 04-11-2021, 01:15 PM RE: How Accurate is Accurate Enough? - Dave Shaffer - 04-11-2021, 02:47 PM RE: How Accurate is Accurate Enough? - lrdheat - 04-11-2021, 02:50 PM RE: How Accurate is Accurate Enough? - Chumango - 04-11-2021, 03:00 PM RE: How Accurate is Accurate Enough? - ttw - 04-11-2021, 03:12 PM RE: How Accurate is Accurate Enough? - Dave Britten - 04-11-2021, 05:29 PM RE: How Accurate is Accurate Enough? - toml_12953 - 04-11-2021 07:26 PM RE: How Accurate is Accurate Enough? - Paul Dale - 04-14-2021, 10:30 AM RE: How Accurate is Accurate Enough? - Garth Wilson - 04-11-2021, 07:50 PM RE: How Accurate is Accurate Enough? - cyrille de brĂ©bisson - 04-14-2021, 07:15 AM

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