On Mon, Oct 31, 2011 at 5:37 PM, David Joyner <[email protected]> wrote: > On Mon, Oct 31, 2011 at 7:31 PM, Aaron Meurer <[email protected]> wrote: >> Comments: >> >> - "as its beautiful logo" should this be "as is its beautiful logo"? > > fixed > >> >> - "However, the most active are..." Maybe rather say "However, the >> most active as of October 2011 are..." to make it clear that this is a >> snapshot into this particular point in time. For example, over the >> summer a different set of developers were most active (i.e., these >> people plus the GSoC students). > > fixed > >> >> - "For example, the following simple Python commands were run from the >> SymPy command line." I would reword this sentence. It sounds like >> SymPy has it's own interpreter, and I think it especially would to a >> user of any other computer algebra system. I'm not sure what the best >> wording is, but make it clear that SymPy just runs inside a normal >> Python interpreter, such as the one that comes with Python or IPython. >> Maybe it would be best to just include a short paragraph about the >> isympy script, which just paraphrases the docstring from that file. > > revised, as suggested > >> >> "Surprisingly, it seems Maxima cannot do this at the present time." If >> I remember correctly, Maxima took the lazy route and only implemented >> second order differential equations (or maybe they can also do higher >> order but only if they are homogeneous, I can't remember). The >> general non-homogeneous case requires either undetermined coefficients >> (if the non-homogeneous term has the correct form), or, in the general >> case, the nth order version of variation of parameters, which is not >> too difficult to implement if you have strong integration routines and >> knowledge of linear algebra (Cramer's rule), but it seems is so rarely >> actually taught that I only found two resources anywhere on the >> internet that dealt with it in the nth case out of the thousands that >> dealt with the 2nd order case, and neither was very good. I discussed >> this on my blog back when I implemented it >> (http://asmeurersympy.wordpress.com/2009/08/01/variation-of-parameters-and-more/). >> In fact, at the time, I couldn't find another open source system that >> implemented this, though I would definitely try to verify this fact >> before putting it in the paper. >> > > I made revisions but I think Axiom has more functionality that Maxima > in this area: > http://www.axiom-developer.org/axiom-website/hyperdoc/equdifferentiallinear.xhtml > > >> "On the >> other hand, perhaps it is not surprising that SymPy is relatively strong in >> the area of differential equations since many or the developers come from >> physics and computational mathematics communities." Actually it's >> mainly because of my GSoC project :) > > > Good point. I changed that. > > New version posted to the usual place:-)
Sorry for my late reply. So here I put your sources to github: https://github.com/certik/oscas-sympy then I sent a pull request with my proposed changes: https://github.com/certik/oscas-sympy/pull/1 you can browse there the total diff, or individual patches. If you want my latest tex file, just download it by clicking here: https://raw.github.com/certik/oscas-sympy/changes/oscas-sympy.tex I am posting here my licence quote that is quoted in the article, so that it is public: " Some people say, that GPL had its place in history. Well, maybe it had, maybe not, it's hard to say - let's leave it for historians. But today in 2011, I think that there is no advantage of GPL over BSD. The only thing that matters is to have a solid community, so that lots of people contribute to the project. Also it seems that these days, there are a lot of people who come to open-source, who don't really feel strongly about licensing, they just want their code to be used (no matter how), and thus use BSD. " Ondrej -- You received this message because you are subscribed to the Google Groups "sympy" group. 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/sympy?hl=en.
