On Sep 22, 4:12 pm, maldun <[email protected]> wrote:
> > Perhaps I should sort out my point before we cause misunderstandings: > It's true that a user familiar with numerics knows about such > behavior. Not necessarily. A user might not even realize that the integrand is oscillatory, and it is somewhat of a specialized area to know about this kind of quadrature. >But since > Sage is a program for a wide range of users, I think it's important to > offer user friendly > integration routines also for people who are beginners, or not so > familiar with that topic. Sure. the goal would be to correctly answer any question, even one from a user who is basically ignorant. Giving right answers to easy questions but wrong answers to difficult questions does not fit the bill. > Perhaps I'm wrong, but isn't it a good thing to open sage to a broader > audience? Sure. > And of course all packages are included in Sage, so it's no big deal > to use them if I want for example > specific integration points. If you want to add extra programs to Sage, you have to provide a route for that "broader audience" to use them, or they will not be used. If you cannot "integrate" such programs smoothly into a grand unified program that does numerical integration in Sage, it is not of much use. > And I don't claim here it's some job for overnight. I'm well aware of > this, but I think it should be considered > as long time goal, and I don't see anything wrong about that, and I > believe it deserves some discussion. Sure. Write NIntegrate from Mathematica. > And since I offer my own manpower and knowledge to > work on this improvements, I personally think it's nothing wrong about > making suggestions, and point out problems. You seem to be claiming you are a novice programmer and you are not (I suspect) skilled in numerical integration technology. So what is wrong with making suggestions and pointing out problems is that your suggestions may be naive, and the problems you point out are not actual problems but merely difficulties YOU have because you are unfamiliar with the standard solution techniques. So that is what is potentially wrong. > But it's quite disturbing for me that something simple like > integrate(sin(x^2),x,0,pi).n() already crashes. Maxima says this is pi/2. If Maxima is being called, then Sage already has access to the answer. If Sage screws this up, maybe it has nothing to do with integration. It has to do with Maxima <--> Sage communication. > But I think there are already some little improvements, which are not > such big deal, e.g. offer the possibility for the user > to set a specific algorithm in the .n(), or distinguish between > integral.n() and n(integral) This is pretty much nonsense for that broader audience. There are substantial numbers of quadrature routines and options in Maxima, if Sage just allows the user to pass these specs through. perhaps you should look into what Maxima offers. > > > There is a great deal written about integration. Perhaps instead of > > offering > > to do some basic programming you could offer to read some books or > > papers on > > numerical integration. Probably the documentation for NIntegrate > > would be a start. > > I think to read documentation and papers is a natural thing. But I'm > not a pro in Python, I didn't suggest you read Python documentation. and will hopefully change that. That's your choice, but my thought is that writing numerical code in Python is generally a bad idea. > I'm just claiming that I can't help out with too advanced programming > skills. It may not take advanced programming skills, but advanced knowledge of numerical methods. If you have neither, you should acquire them. -- To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
