# Suggestion

Wols Lists antlists at youngman.org.uk
Wed Jan 13 08:49:32 PST 2016

```On 12/01/16 21:11, Rick C. Hodgin wrote:
> The values won't round.

You misunderstand me. They shouldn't round.

And based on what the user has selected, they
> will display to the nearest power of 3 (10^(k*3)), or in an explicit
> form.  The default option will be to auto-range the values into their
> metric named range.

That's the point. THIS BEHAVIOUR IS WRONG. You should NOT range to the
*nearest* power of three, you should range to the *most* *appropriate*
power of three.

Let's say I have two numbers, 1.234^x and 0.1234^x. One is less than 1,
one is greater than 1. Forget the exponent x, the point is you should
NEVER mix mantissae like that. It's not that one is wrong and the other
is right, it's that consistency is important, some people insist on one,
others insist on the other.

If the user explicitly says they want nano-units, then give them
nano-units, fine. But if you're auto-ranging it, you should NEVER mix
mantissae - you can force it to 0.001234^(x+3) and 0.1234^x, or you can
force it to 1.234^x and 123.4^(x-3).

You can see - the mantissae are BOTH greater than 1, or BOTH less than
1. Some situations demand the first, some situations demand the second.
I think at school in Physics I always used the second - the mantissa had
to be greater than 1. I've been in situations where people insisted it
had to be less than 1.

(You see the same argument when using "Exponential Notation" - is the
integer part of your mantissa ALWAYS zero eg 0.1234^x, or NEVER zero eg
1.234^x).

Cheers,
Wol
>
> Here are some examples:
> http://www.libsf.org/misc/libreoffice_metric_example.ods
>
> Best regards,
> Rick C. Hodgin
>
>
> On Tue, Jan 12, 2016 at 2:55 PM, Anthonys Lists
> <antlists at youngman.org.uk <mailto:antlists at youngman.org.uk>> wrote:
>
>     On 12/01/2016 13:22, Rick C. Hodgin wrote:
>
>         The important part of the Metric feature is that it always wraps
>         the value to the nearest power of 3, and shows values in those
>         powers.  0.1234 would be shown as 123.4 milliunits, or 1,234
>         microunits, for example (however the user has set it up), and
>         not as "0.1234 u" (unless they are explicitly stating to use
>         "Units", which would be something they'd have to do manually).
>
>
>     I'm not sure of the name, but the user might not want it to be in
>     whole units. Note that 0.1234 is a power of 3, and the user might
>     want it to be *0*.1234 UNITS.
>
>     So yes, I like the idea of displaying it to a power of three, but it
>     needs a switch to say "greater than one or less than 1?", so that
>     0.012 units might stay 0.012 units, or might become 12 milliunits.
>
>     imho rounding to the *nearest* power of 3 is a mistake - users
>     invariably want either greater, or less, than one, but NEVER a mix
>     of both.
>
>     Cheers,
>     Wol
>
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>

```