GNU bug report logs - #10554
24.0.92; No units specified (dimensionless quantities in Emacs Calc)

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From: Jay Belanger <jay.p.belanger <at> gmail.com>
To: "Roland Winkler" <winkler <at> gnu.org>
Cc: 10554 <at> debbugs.gnu.org, jay.p.belanger <at> gmail.com
Subject: bug#10554: 24.0.92; No units specified (dimensionless quantities in Emacs Calc)
Date: Fri, 20 Jan 2012 13:10:22 -0600

>> > I would always consider the concept of "converting part of a units
>> > expression" to be not the main rule to follow here,
>>
>> If 45 mi/hr is on the stack, and "u c" is called with new units km, what
>> should happen?
>
> Here the user is posing a problem with no uniquely defined answer.
> The answer could be expressed in km/hr but also in km/s or in km eV/hbar.

But what /should/ happen?  Would you like an error signaled?  Otherwise,
the current behavior is the most reasonable.

>> But what if you ask Calc to convert a units expression into a
>> dimensionless number when it can't be so converted?
>
> again: I'd give this scenario the lowest priority.

I'm not sure what you mean by giving it low priority. 
Either it happens or it doesn't, and Calc needs to do something if it
happens.

> In physics I'd call "1" a unit like all the other ones. In that sense
> it would be great if Calc could treat it that way, too.

Calc does that; it looks to me as if you want it treated special.

It seems to me as if you want to get rid of Calc's ability to deal with
inconsistent units, but that's pretty established Calc behavior.

Jay

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