00:37 Anyone alive? 00:45 -!- faroe(n=faroe@port487.ds1-od.adsl.cybercity.dk) has joined #maxima 01:04 -!- eggauah(n=daniel@20845108.cps.virtua.com.br) has joined #maxima 02:33 -!- Prax01D(n=Prax01D@tor58-4-75-69.dynamic.rogerstelecom.net) has joined #maxima 03:18 -!- deathwarrior(i=deathwar@unaffiliated/deathwarrior) has joined #maxima 03:18 Hi everybody 03:18 I'm trying to do: integrate(3*sin(x)^2+cos(x),x,0,2); 03:19 But I just got something like 3*sin(4 03:19 (3*sin(4)-4*sin(2)-12)/4 03:20 is there some way to tell maxima to evaluate that expresion? 03:44 -!- trebor_home(n=trebor@dslb-084-058-235-105.pools.arcor-ip.net) has joined #maxima 03:45 -!- trebor_home(n=trebor@dslb-084-058-235-105.pools.arcor-ip.net) has left #maxima 04:29 -!- trebor_home(n=trebor@dslb-084-058-235-105.pools.arcor-ip.net) has joined #maxima 04:30 04:30 *** You have joined channel #maxima [21:05] 04:30 *** Topic for #maxima: - a free computer-algebra-system - paste here: 04:30 http://paste.lisp.org/new/maxima 04:30 *** #maxima: topic set by trebor_dki, 14:56:01 2005/12/15 04:58 -!- trebor_home(n=trebor@dslb-084-058-235-105.pools.arcor-ip.net) has joined #maxima 06:34 -!- stw_(n=stw@e176185246.adsl.alicedsl.de) has joined #maxima 06:58 deathwarrior: here? 06:59 Append ",numer": 06:59 integrate(3*sin(x)^2+cos(x),x,0,2), numer; 08:35 -!- Prax01D(n=Prax01D@tor58-23b-95-10.dynamic.rogerstelecom.net) has joined #maxima 10:15 -!- szymon(n=szymon@cad170.neoplus.adsl.tpnet.pl) has joined #maxima 11:25 -!- cunzhang(n=apzc2529@218.7.43.195) has joined #maxima 14:36 -!- Prax01D(n=Prax01D@tor58-23b-95-70.dynamic.rogerstelecom.net) has joined #maxima 15:14 -!- cunzhang(n=apzc2529@218.7.43.195) has joined #maxima 15:37 -!- turn-omg(n=turn-omg@FLH1Aah107.fki.mesh.ad.jp) has joined #maxima 15:52 -!- eggauah(n=daniel@20845108.cps.virtua.com.br) has joined #maxima 16:07 -!- szymon(n=szymon@bzh9.neoplus.adsl.tpnet.pl) has joined #maxima 16:12 -!- turn-omg_(n=turn-omg@FLH1Aah107.fki.mesh.ad.jp) has joined #maxima 16:13 -!- turn-om__(n=turn-omg@FLH1Aah107.fki.mesh.ad.jp) has joined #maxima 16:19 -!- szymon_(n=szymon@cad196.neoplus.adsl.tpnet.pl) has joined #maxima 16:57 -!- szymon_(n=szymon@bzk191.neoplus.adsl.tpnet.pl) has joined #maxima 18:04 -!- gabkdlly(n=gabriel@dslb-088-073-128-085.pools.arcor-ip.net) has joined #maxima 18:29 -!- lisppaste4(n=lisppast@common-lisp.net) has joined #maxima 19:11 Anyone alive? 19:26 -!- szymon(n=szymon@cbh94.neoplus.adsl.tpnet.pl) has joined #maxima 19:48 -!- HaraldG(n=rldprog@g4v1.g4.wien.funkfeuer.at) has joined #maxima 19:50 Anyone alive? 19:59 Not sure yet ... 19:59 Good evening, HaraldG. 20:00 I have a question about integration. 20:01 Feel free to ask it here. 20:03 I'm trying to integrate various stuff of this kind: 20:03 integrate(x^2/(exp(x)-1), x, 0, inf) 20:04 Maxima returns rather lengthy answer, with limits. 20:04 But the integral is well known. 20:04 How can I teach Maxima? 20:04 Well, seems maxima doesn't know too much about polylogarithms ... 20:05 really good question, i am still working on trying to figure out how to use slime to debug maxima 20:05 (superior lisp evaluation mode for emacs) 20:05 Another question is about PDEs. 20:06 Alright, there's no support. 20:06 ASau: Don't give up that fast. :) 20:06 But how can I substitute variables in DEs? 20:06 Like rect. to polar and v.v.? 20:07 Do you think maximas answer (with the limit) is useful to calculate the final answer? Do you know how to solve the problem by hand? 20:07 (Sorry, I'm not an expert on polylogarithms either.) 20:08 HaraldG: I don't know. 20:08 But there's exact result, which could be reused. 20:08 I'm not even mathematician. 20:08 My domain is physical chemistry. 20:10 Yes, your integral looks somewhat familiar to me. Bose-Statistics? 20:10 Right. 20:12 I would like to start working, but I need a boost. 20:12 Rational functions are too primitive. 20:13 I can help you a bit with the technical details, but I'm afraid I can't help you with the math behind your problem... Perhaps it's best to ask on the mailing list. 20:14 Well, technical problems first. 20:14 Is there any overview, how simplification is done? 20:14 Integration too. 20:16 You mean the core simplifier that handles 1+1 or external simplifier like expand, factor, ratsimp, trigsimp, etc.? 20:17 The integration code is a mess. 20:17 Well, lets' start from simple things then. 20:17 Does "core simplifier" perform a kind of search? 20:18 Or does it work rather straightforward? 20:20 The core simplifier (i.e. any simplification performed automatically) is designed to be fast and straigt forward and not to do anything which might anoy you. 20:20 Basically it tries to bring the expression at hand to some canonical form... 20:20 ... reordering terms in sums and products ... 20:21 ... getting rid of extra parenthesis between n-nary operators, etc. 20:23 So, it doesn't perform search, it just applies reducing productions, right? 20:26 Let's say it shouldn't do any search. I wouldn't be surprised if it sometimes did for the more obscure operators ... 20:28 BTW, if you're interested, that's how you can find the integral above: 20:28 'integrate(8*%pi*nu^2/(c^3) * 1/(exp((h*nu)/(k*T))-1), nu, 0, inf); 20:28 changevar(%, x - (h*nu)/(k*T), x, nu); 20:28 No idea, why it leaves h^3 under integral. 20:29 Not even notices common multiplicand. 20:32 Yes, this is a feature: As said above, the core simplifier should do anything that potentially might anoy anybody: Especially it doesn't try to find common factors or distribute factors over terms... 20:33 See a*(b-c/a) for example. 20:41 -!- Prax01D(n=Prax01D@tor58-4-74-122.dynamic.rogerstelecom.net) has joined #maxima 20:44 -!- deathwarrior(i=deathwar@unaffiliated/deathwarrior) has left #maxima 20:46 'integrate(integrate(integrate(1/(exp((h*(nux^2 + nuy^2 + nuz^2)^(1/2))/(k*T))-1), nux, minf, inf), nuy, minf, inf), nuz, minf, inf); 20:46 Why does it ask questions about "x" and "y"? 20:54 No 3D integrals? 20:55 Well, let's make it cylindrical at least. 21:05 -!- HaraldG(n=rldprog@g4v1.g4.wien.funkfeuer.at) has joined #maxima 21:06 ASau: Sorry, lost my network connection. 21:08 Yes, the questions about xy are odd. Seems it does some internal substitutions but then can't figure out the sign. 21:08 That sure is a bug. 21:13 Is there a way to trace evaluation? 21:14 I undestand, it may be quite large, but I don't fear lisp. 21:24 If you are familiar with the lisp debugger, then I guess so. (I'm not) 21:39 -!- faroe_(n=faroe@port487.ds1-od.adsl.cybercity.dk) has joined #maxima 22:28 HaraldG_log: I know, how it is done by hand. 22:28 The function is analytic, thus you can integrate over contour. 22:28 Say, embracing upper half-plane. 22:29 Thus, you need to find residuals at points where exp(z/a)=1. 22:29 All of them lie on imaginary axis. 22:29 Thus, you have an infinite sum. 22:30 The latter reduces to zeta function with multiplicand, IIRC. 22:53 Is it possible to compute complex logarithm? 22:53 Not just principal branch. 23:19 -!- Aattila(n=attila@146.110.58.183) has joined #maxima 23:27 Good evening, Aattila. 23:28 hello ASau 23:28 Do you know, how can I get complex logarithm? 23:29 I need to expand log(1) to all branches. 23:36 sorry, I can't help you, I'm just a beginner 23:52 -!- ASau(n=user@79.111.27.241) has joined #maxima