I am not sure but I think that would take a lot of time. I think we have to expose both number of coefficients and the ranges (a, b) and let the user decide.
I think I can send a pull request regarding this soon(weekend). -- Bharath M R 5th Year undergraduate student, IIT Madras catchmrbharath.github.com Sent with Sparrow (http://www.sparrowmailapp.com/?sig) On Thursday, 4 October 2012 at 8:54 PM, Ondřej Čertík wrote: > On Thu, Oct 4, 2012 at 8:02 AM, Fredrik Johansson > <[email protected] (mailto:[email protected])> wrote: > > On Wed, Oct 3, 2012 at 2:12 AM, Ondřej Čertík <[email protected] > > (mailto:[email protected])> wrote: > > > Hi, > > > > > > Does anyone have experience with implementing rational function > > > approximations > > > to a given special function of one variable? This would be extremely > > > useful addition > > > to sympy. Here is an example for the error function from the standard > > > gfortran library: > > > > > > > > > This is something I've needed quite frequently, but I've never been > > bothered enough to code it myself. I usually just use Mathematica > > (EconomizedRationalApproximation or MiniMaxApproximation). It would be > > great to have in sympy or mpmath. > > > > > Yes, this is it --- we need these two functions. I didn't know that > Mathematica > had it, nice. > > I've been thinking how to automatically cover the whole interval let's > say (0, oo) > and I would simply pick "m, n", then start on (0, a), call > EconomizedRationalApproximation, check > the error, if it is lower than 1e-18 (absolute error and probably also > some relative error), > then increase "a". Once we have the maximum "a", we do the interval > (a, b) and maximize > "b". And so on. > > Ondrej > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to [email protected] > (mailto:[email protected]). > To unsubscribe from this group, send email to > [email protected] > (mailto:[email protected]). > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
