I guess I'd like to see code like the following >>> sy.jacobi_normalized(2, 0, 1, x) sqrt(6)*(5*x**2/2 - x - 1/2)/2
>>> with evaluation(False): ... sy.jacobi_normalized(2, 0, 1, x) sqrt(6)/3*jacobi(2, 0, 1, x) But yes, I suppose we could just capitalize the jacobi class and add an evaluate= keyword. That will probably resolve Freddie's immediate issue. It's good practice in any event. On Wed, Feb 5, 2014 at 3:40 PM, Ondřej Čertík <[email protected]>wrote: > Isn't the solution simply to provide a class Jacobi, that is not > evaluated, and a function jacobi(), that does what it does now? > > Ondrej > > On Wed, Feb 5, 2014 at 4:38 PM, Matthew Rocklin <[email protected]> > wrote: > > Although, I don't know much about the polynomials module. It may be > > possible to resolve the problem there without tackling the problem at > large. > > > > > > On Wed, Feb 5, 2014 at 3:29 PM, Matthew Rocklin <[email protected]> > wrote: > >> > >> Unwanted automatic evaluation comes up fairly frequently on the > listhost. > >> It's on our radar but there hasn't been much movement on the issue > lately. > >> It requires a concerted effort by someone with some time. > >> > >> > >> > is there wider interest in such a feature? > >> Absolutely. > >> > >> > >> On Wed, Feb 5, 2014 at 2:54 PM, Freddie Witherden < > [email protected]> > >> wrote: > >>> > >>> Hi all, > >>> > >>> In SymPy is there any way of stopping orthogonal polynomials from > >>> automatically simplifying down to concrete expressions? So for: > >>> > >>> sy.jacobi_normalized(2, 0, 1, x) > >>> > >>> to give: > >>> > >>> sqrt(6)/3*jacobi(2, 0, 1, x) > >>> > >>> as opposed to: > >>> > >>> sqrt(6)*(5*x**2/2 - x - 1/2)/2 > >>> > >>> I have a use-case where it is highly desirable for polynomials to be > >>> kept in the above form (as it permits more efficient/numerically stable > >>> evaluations later on). Other than keeping n as a Symbol is this > >>> currently possible? If not---and I suspect, from a quick glance over > >>> the source code that it isn't!)---is there wider interest in such a > >>> feature? > >>> > >>> Regards, Freddie. > >>> > >> > > > > -- > > 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. > > For more options, visit https://groups.google.com/groups/opt_out. > > -- > 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. > For more options, visit https://groups.google.com/groups/opt_out. > -- 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. For more options, visit https://groups.google.com/groups/opt_out.
