[sympy] Making orthogonal polynomials more symbolic

2012-07-13 Thread rl
There is an old open PR: http://github.com/sympy/sympy/pull/1026 which tries to make orthogonal polynomials work for symbolic order 'n'. An open question is when to apply simplifications like: L_n(-x) --- (-1)**n * L_n(x) L_{-n}(x) --- L_{n-1}(x) Do we want to have this: a) at

Re: [sympy] Making orthogonal polynomials more symbolic

2012-07-13 Thread rl
No, at the moment both options do not allow to compute the orthogonality integrals :-/ @asmeurer: I remember we once tried computing that: In [2]: n = Symbol(n) In [3]: m = Symbol(m) In [4]: x = Symbol(x) In [5]: dln = diff(legendre(n,x),x) In [6]: dln Out[6]: n*(x*legendre(n, x) - legendre(n -

Re: [sympy] Making orthogonal polynomials more symbolic

2012-07-13 Thread rl
What if either argument is something like x - y or y - x? Would those both be canonicalized to the same thing (with either choice)? No. a) We pull out some factors and get legendre objects of same argument: In [6]: legendre(n, y-x) Out[6]: (-1)**n*legendre(n, x - y) In [7]: legendre(n, x-y)

[sympy] Name of elliptic integrals

2012-07-08 Thread rl
Which names should we choose for the elliptic integral functions in PR 1408? -- You received this message because you are subscribed to the Google Groups sympy group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to

Re: [sympy] Re: can not do integral of sqrt(sin(x))

2012-07-07 Thread rl
A first start: http://github.com/sympy/sympy/pull/1408 -- You received this message because you are subscribed to the Google Groups sympy group. To view this discussion on the web visit https://groups.google.com/d/msg/sympy/-/vkHPwsB_yYAJ. To post to this group, send email to

Re: [sympy] can not do integral of sqrt(sin(x))

2012-07-06 Thread rl
The problem I see is *how* to add these to the integration routines. There is no nice Meijer-G representation. And I suppose that Risch can not handle these. At least not w/o major extensions. -- You received this message because you are subscribed to the Google Groups sympy group. To view this