On Mon, Oct 31, 2011 at 6:37 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 >
Ah, that's not surprising. Axiom probably implements something like http://www-sop.inria.fr/cafe/Manuel.Bronstein/sumit/bernina_demo.html. Aaron Meurer > >> "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:-) > > Thanks Aaron! > >> >> Aaron Meurer >> >> On Mon, Oct 31, 2011 at 4:33 PM, David Joyner <[email protected]> wrote: >>> On Sun, Oct 30, 2011 at 12:48 PM, Vladimir Perić <[email protected]> >>> wrote: >>> >>> ... >>> >>>> >>>> I also think the "Capabilities" section is a bit.. short. You took it >>>> from the website, I assume? That homepage hasn't been updated in a >>>> long time (and writing that list is even one task for Google Code-In). >>>> At the very least, I think you should give more mention to the physics >>>> and quantum modules, which is a real advantage SymPy has over other >>>> CAS systems. >>> >>> >>> After a few emails from Brian Granger (thanks Brian!) I have >>> created a new subsection on quanum physics. It is very sketchy >>> but hopefully has enough for interested readers to pursue >>> further leads. >>> >>> Latest version is at >>> http://boxen.math.washington.edu/home/wdj/sigsam/sympy/oscas-sympy.pdf >>> (and sources are in that directory too). >>> >>> BTW, if anyone wants to post this to github, that is fine with me. >>> However, I know >>> zip about git:-) >>> >>> >>> Thanks to all of you for your great help! >>> >>>> >>> >>> ... >>> >>>> -- >>>> Vladimir Perić >>>> >>>> -- >>>> 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. >>>> >>>> >>> >>> -- >>> 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. >>> >>> >> >> -- >> 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. >> >> > > -- > 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. > > -- 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.
