[Om] Questions about representing units

mdt22 at bath.ac.uk mdt22 at bath.ac.uk
Sat Feb 21 22:15:22 CET 2009

Dear Christoph,

I am currently taking on the project titled: Development of an  
extensible OpenMath-based unit converter.

At the moment i am about 2 weeks into the implementation and have  
almost finished getting the system working with command line, then the  
next stage for me is to get it working as a web service and hence  
getting the two ends talking to one another (this sounds like  
something u are trying to achieve to!).

Hopefully in the next couple of weeks there will be a web version  
accessible to all (i'll let you know when its avilable).

tbh my time is quite limited; at the moment i have just limited the  
input/output units to only converting between matching same dimensions  
as given in the .sts files, also i am finding it hard to get  
speed/accelerations working since they are quite different than  
standard units.

I hope thats useful to you, let me know any questions you have.



Quoting Jonathan Stratford <jonathanstratford at hotmail.com>:

> Hi Christoph,
> By "service", are you envisaging a proper web service? I don't know much
> about those, and my program isn't one -- just a standard exe with a PHP
> front-end. As such I'm not sure how easily you could integrate it into
> anything else. You're welcome to try though!
> I'm happy to give you my program...I've actually fixed the bug that caused
> the problem you mentioned earlier, although I've by no means completely
> tested the changes. I'll send that to you separately in a minute, as it's
> probably not fair to spam everyone with it! It just runs under mono quite
> happily -- in actual fact klein is a Mac, but I guess mono runs the same
> anywhere.
> Using WinSCP also occurred to me this evening, but klein seems to be down,
> so can't get very far!
> Yes, there's another student continuing the work, but I'm not sure what he's
> doing in terms of where he's extending my program. I hadn't thought about
> releasing the code under licence..no idea how I'd go about doing so, but it
> might be a good idea if I could find out what it entails.
> Cheers,
> Jonathan
> ----- Original Message -----
> From: "Christoph LANGE" <ch.lange at jacobs-university.de>
> To: "Jonathan Stratford" <jonathanstratford at hotmail.com>
> Cc: "Professor James Davenport" <jhd at cs.bath.ac.uk>; "OpenMath"
> <om at openmath.org>; <mdt22 at bath.ac.uk>; <jap at cs.bath.ac.uk>;
> <jonathan.stratford at alumni.bath.ac.uk>; "Jana Giceva"
> <j.giceva at jacobs-university.de>
> Sent: Saturday, February 21, 2009 7:57 PM
> Subject: Re: Questions about representing units
> Hi Jonathan,
> On Saturday 21 February 2009 14:46:31 Jonathan Stratford wrote:
>> >BTW, does your unit converter
>> >(http://klein.activemath.org:90/~jonathan/units/converter.php) support
>> > such compound units for which no explicit symbol has been defined?
>> Yes, it can cope with many of these (it can't cope with all of them as the
>> algorithm's by no means perfect).
>> ...
>> 17.3 millimetre per nanosecond sqrd to mile per hour sqrd
>> 6 ounce inch per minute sqrd to kilogramme metre per second sqrd
> OK, thanks!  The reason for my questions is not that we need a perfect unit
> conversion service, but some nice service on the web that we can integrate
> with our (inter)active documents for demo purposes.  Then, depending on the
> acceptance of that idea, the next requirement would be a better unit
> conversion service ;-)
>> For some reason, I can't get the online version to load
> It worked for me yesterday, but not today.  Anyway: Is there any way to
> obtain
> your source code, or the compiled version?  Not sure what one needs for
> running this on Linux (just a .NET environment like Mono?), but I suppose
> that
> klein.activemath.org is a Linux server as well.
>> >> 1 hour to second is incalculable.
>> ...
> I see -- thanks for your explanation!  Anyway, we don't require this
> conversion to work at the moment, but it just struck me that such a simple
> conversion was reported to be impossible.
>> "Something that needs considering in OpenMath, but which has quite
>> wide-ranging consequences for our system is whether it is correct for a
>> unit name to appear in two different CDs, both to represent the same unit,
>> as with second, or a different unit. This affects how the units are stored
>> and looked up."
> For general OpenMath symbols, this has to be possible, of course, but I see
> that it might be something between bad style or illegal for OpenMath symbols
> that represent units.
>> I have no way of updating the version on klein.activemath.org (I never had
>> FTP access, only scp, so I used my uni webspace to copy from). It has just
>> occurred to me that I could possibly do it through cygwin, so I will try
>> to
>> give it a go later on -- but it seems the server is down currently.
> How about WinSCP?  That's a more convenient alternative.
>> >Is there any better place for reporting this bug?
>> I imagine I'm the only one worth reporting bugs to, as I don't think
>> anyone
>> else is likely to work on it.
> Didn't James mention one other person who might possibly continue this
> project?  Or, on the other hand, how about releasing your code under an open
> source licence and hoping for somebody else to help you?
> Thanks again for your help!
> Cheers,
> Christoph
> --
> Christoph Lange, Jacobs Univ. Bremen, http://kwarc.info/clange, Skype
> duke4701

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