To be honest, I'd have thought that installing a python package and let it work with SAGE would have been easier, but one issue could be that I've been working on this in a Saturday night (after coming back home) from midnight to 1.30 am!! :)
I summarize the way I got "quantities" (http://pypi.python.org/pypi/ quantities) installed at the end (consider I'm using a VMWare virtual machine from XP): 1. login as manage 2. sudo su 3. type sage -sh to go into the sage environment 4. unpack and install quantities 5. run SAGE and python and test The first test failed. I mean, I got it installed and running: 1) unpack the quantities-0.5b2.tar.gz 2) python setup.py install The result is not satisfying me: 1) if I run python from that sage -sh shell, I can use quantities in the same way they show in the tutorial (http://packages.python.org/ quantities/user/tutorial.html). They seem to clearly claim that quantities is still in an advanced beta development phase, so it's not fully documented, nor available for production (yet). I can confirm, the documentation seems missing: example import quantities as pq pq.Quantity? File: /usr/local/sage/local/lib/python2.5/site-packages/ quantities-0.5b2-py2.5.egg/quantities/quantity.py Type: <type 'type'> Definition: pq.Quantity( [noargspec] ) Docstring: x.__init__(...) initializes x; see x.__class__.__doc__ for signature That's it! Seems poor... 2) The biggest issue is that I can't get it to work within a SAGE notebook: from numpy import * import quantities as pq res = 10*pq.ohm Traceback (click to the left for traceback) ... TypeError: unsupported operand parent(s) for '*': 'Integer Ring' and '<class 'quantities.unitquantity.UnitQuantity'>' I'm really not that good with all this stuff, but my understanding is that, whenever you try to define a new object like an integer or a float number times a "quantities" unit, it somehow forces the number to become a numpy array. This seems to fail within a SAGE notebook. Any idea on how this could be fixed, or otherwise should be not? I am just talking out of couple of minutes working on it, I admit it. Anyway, I'll try to get the other packages installed as well, although I am not sure when. Any other suggestion or comment is very well accepted! Final comment: should I have done any other sage command to let it reload or synchronize the newly installed sage packages, before running the notebook? Thank you Maurizio Maurizio On 14 Mar, 09:21, Jason Grout <jason-s...@creativetrax.com> wrote: > Maurizio wrote: > > Hello, > > I'm forwarding this to sage-devel as well, maybe being the most > > appropriate group to address this issue. > > > I'm a happy user of SAGE, and I won't stop thanking all you guys for > > this wonderful job! Although, I also try to encourage you in getting > > something better (from my point of view). > > > It seems there has been some serious thinking about including a UNITS > > of MEASUREMENTS managing package in SAGE: > >http://groups.google.com/group/sage-devel/browse_frm/thread/8791448b7... > > > From this, a SAGE trac ticket has been opened (#3852): > >http://trac.sagemath.org/sage_trac/ticket/3852 > > > This is supposed to be a MAJOR priority ticket, and I think this is a > > very appropriate description! > > I agree. I should also add that nearly every ticket in trac is marked > as major priority. Indeed, there are lots and lots of things to do on > Sage. That's why we really appreciate your help! > > > The ticket has a very good (although a bit old now) description of the > > different packages available to deal with units in Python. One of the > > options, was the units package included in Enthought. This had the > > issue of being under refactoring at that time. > > > The actual situation seems to be that the Enthought package has not > > been changed (https://svn.enthought.com/enthought/ticket/1524) because > > of some priority issues in that community (very understandable!), but > > another interesting package was born from this Enthought discussion: > > the "quantities" package: > >http://packages.python.org/quantities/ > >http://dale.chess.cornell.edu/chess-wiki/Quantities > > Thanks for tracking this down. I wondered if it would ever get > refactored. What do you think of the Quantities module? I browsed > through the documentation and it looked very interesting. On the plus > side, it's being actively developed now, which I think sets it apart > from any of the other solutions, right? > > > As I can see, this has already been mentioned in a comment to our trac > > ticket, but with no response. > > > Honestly, I am not able to understand whether this is good enough to > > be included in SAGE, neither I am able of understanding how much > > refactoring this would need to make this compatible to all the > > wonderful symbolic capabilities of SAGE, but nonetheless I think that > > getting something working at least in the numeric domain, could be > > very useful > > > With this, I'm not proposing this package over others (for example, > > Unum looks very mature, but outdated), I'm just asking if one of you > > can spend some minutes to review our trac ticket about units of > > measurement (#3852), and to take some other decision about it. > > Which package do you prefer? I think at this point, someone needs to > just make a decision with one of the packages and justify it on > sage-devel. Preferably, that person would offer instructions to install > the top one or two (or three?) choices so that people could try them > out. They would probably also give examples of syntax so others could > see (and maybe compare that to the syntax of the other packages). > > Installation is easy if you are familiar with the command line. Just do: > > $ sage -sh > > Then follow whatever instructions the package gives for installation. > That will install the package into Sage's python library. > > Thanks, > > Jason --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
