And regarding assumptions I agree with everything that you said.
On Mon, Mar 31, 2014 at 8:14 PM, Matthew Rocklin <[email protected]> wrote: > http://www.evanmiller.org/mathematical-hacker.html > > I reference that blog post pretty often. I fully intend to reference it > again in my talk (if it is accepted). > > The interesting thing about the Factorial / Gamma / loggamma example is > that to find the solution you need to find someone who knows both that n! = > Gamma(n+ 1) *and* who knows that a loggamma routine is commonly found in > lower level languages. Those bits of information are usually held by > different experts. Ondrej said "Of course, that's obvious" when I first > reposted the article on G+. > > You're right that this is similar to my last talk. The last one though > was mostly about an application (numerical linear algebra). I actually > want to talk a bit more about the philosophy and some of the more abstract > tools that people might actually use. Your first impression is a valuable > one though, I should go through my last talk and make sure that I'm not > repeating too much that shouldn't be repeated. > > > On Mon, Mar 31, 2014 at 6:03 PM, Aaron Meurer <[email protected]> wrote: > >> That's a good point. One of the nicest things about symbolics, when you >> can get it, is that it can make things drastically more efficient by doing >> mathematical simplifications. Evaluating integrals symbolically is a nice >> example of this (especially for SymPy, which has some pretty nice >> algorithms to compute definite integrals). >> >> I'm reminded of a popular blog post (I can't find a link right now) about >> how know math is important for programmers. It has the example of how all >> these programming languages show how they they compute factorial, and how >> tail recursion can make it linear or whatever, but the actual best way to >> compute it is to use loggamma, which gives the answer in constant time. >> >> Aaron Meurer >> >> >> On Mon, Mar 31, 2014 at 7:51 PM, Tim Lahey <[email protected]> wrote: >> >>> >>> >>> On 31 Mar 2014, at 20:29, Aaron Meurer wrote: >>> >>> On Mon, Mar 31, 2014 at 11:32 AM, Matthew Rocklin <[email protected] >>>> >wrote: >>>> >>>> I like that you emphasized the utility for numerics, I think that this >>>>> is >>>>> likely to be a selling point for the SciPy crowd. >>>>> >>>>> >>>> Yes, this was very intentional. I may need some help gathering up some >>>> nice >>>> motivating examples if this is accepted. >>>> >>> >>> One motivating example for me is the integration of products of >>> functions over areas and volumes. For finite elements, you'll get products >>> of pairs of trial functions (usually polynomials). It's even more useful >>> for products of trig functions. Performing the integration of any of theses >>> is easy enough with numerical integration, but it's much more efficient to >>> calculate the integrals symbolically and then perform the evaluation for >>> each element. >>> >>> Cheers, >>> >>> Tim. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "sympy" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at http://groups.google.com/group/sympy. >>> To view this discussion on the web visit https://groups.google.com/d/ >>> msgid/sympy/AE5C61B5-8C69-49AE-BAFF-85E5AC924F8F%40gmail.com. >>> >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sympy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sympy. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/CAKgW%3D6K8F9weBP-7yjpzrN9hQ5FR54TK_QdCPqbzBdwo20zKdg%40mail.gmail.com<https://groups.google.com/d/msgid/sympy/CAKgW%3D6K8F9weBP-7yjpzrN9hQ5FR54TK_QdCPqbzBdwo20zKdg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAJ8oX-HL231yvo9QA2ewd%3DC%3D8CCrDn-W4obRtJfYp%3DArP8r0fQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
