William Stein wrote: > Since you've clearly been thinking of this from a developer's perspective, > and maybe even spending a lot of time writing code, is there any > chance you could just dump some of your design thoughts in an > email here?
I'll try to come up with some coherent description & post it here. > (1) Are the list of all units one uses pretty standard? Is there > a table, say in Wikipedia, with pretty much all of them? Or do > people make up new units in the course of their work or research? Well, from what I can tell in any given field most work is done with a relatively small set of units which are conventional for the field. The union of all units in all fields is fairly extensive though. Any computerized units system would have to include the SI units. Beyond that, there are so-called customary units (feet, pounds, etc) which are still widely used in the US; I am not aware of other non-SI systems in extensive use. I think it's fairly common to see semi-SI units such as MJ/day or mg/kg. I think it's common enough to invent to invent new units like those for convenience. The implication, to me, is that any units system has to be easily extensible, since it's likely that random users would want units that escaped our notice. > (2) Are there *any* difficult algorithms that involve units or is this > mostly a notational and representation problem plus some algebra > and simplification? There's isn't really anything too complicated -- probably the most complex operation in the ezunits package is to solve a system of linear equations. Most of the fun seems to be in the notation and representation. Maybe there would be some interesting algebra problems if only I had more imagination. > (3) Does Maxima, Maple, Mathematica, Matlab or Axiom do anything > particularly cool, surprising or clever involving units? I have looked around to see what Maple and Mathematica have in the way of units, but from what I have seen, there is nothing very exciting. Which is OK --- something boring which just works right would be very useful. FWIW Robert Dodier --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
