Re: standard units in software

[Eugene Chudakov <gen@jlab.org>]

Hi Matt,

the scheme you suggest is convenient for local
calculations, but how do you transfer variables to another
routines? You still seem to need a convention or another call
parameter to define the unit...

Regards,
Eugene


On Mon, 24 Nov 2008, Matthew Shepherd wrote:

>
> In CLEO we had a set of constants defined in a file called units.h
>
> One would then write things like:
>
> 0.25*k_GeV, 120*k_MeV, 15*k_m, ...
>
> The constants were multiplicative factors to convert the numbers to standard 
> units.  This was very nice since one never had to think about what the 
> standard units were and the code looks much nicer:
>
> if( energy > 30*k_MeV ){
> ...
> }
>
> I would advocate a similar approach for us.
>
> -Matt
>
>
> On Nov 24, 2008, at 9:13 AM, David Lawrence wrote:
>
>> 
>> Hi Mark,
>>
>>  I distinctly remember discussing this at a software meeting a long time 
>> ago. However, it does not appear to have made it into the coding 
>> conventions and a quick scan of meeting minutes was none too fruitful.
>>
>>  I think we should add this to the coding conventions with the exact units 
>> you suggest using Tesla for the magnetic field. Would you mind adding the 
>> entry to the coding conventions wiki page? Then, we can discuss it and 
>> ratify it at the software meeting next week.
>> 
>> Regards,
>> -David
>> 
>> Mark M. Ito wrote:
>>> Folks,
>>> 
>>> Do we have an official set of standard units written down somewhere? I am 
>>> talking about things like
>>> 
>>> centimeters
>>> nanoseconds
>>> GeV
>>> Tesla? kilogauss?
>>> 
>>> where one can assume a given quantity in the software is in standard units 
>>> unless stated otherwise explicitly.
>>> 
>>> -- Mark
>>> 
>> 
>> -- 
>> 
>> ------------------------------------------------------------------------
>> David Lawrence Ph.D.
>> Staff Scientist                 Office: (757)269-5567   [[[  [   [ [ 
>> Jefferson Lab                   Pager:  (757)584-5567   [  [ [ [ [ [ 
>> http://www.jlab.org/~davidl     davidl@jlab.org         [[[  [[ [[ [[[
>> ------------------------------------------------------------------------
>> 
>> 
>