using pade approx
Hi 1) From the only example I found s = PowerSeriesRing(QQ,'s').gen() a=exp(s);a.pade(4, 0) type(a)
it seems this works for type 'sage.rings.power_series_poly.PowerSeries_poly'
But I have a type 'sage.symbolic.expression.Expression' b, and was unable to convert b to the type required to apply pade
2) There's an alternative rational.reconstruct , but that seems to be geared to computations modulo (n) 3) In conclusion, it seems at current stage the simplest is to write one's own Pade? Thanks, Florin
bfrom (1), so that potential helpers have a clear idea what kind of expressions are involved, and give the solution working in that particular case in any case.rational_reconstruction, indeed. But i do not see it as an alternative, it is designed only for the special use described in its doc string, offered e.g. by typingrational_reconstruction?in the sage interpreter.pademethod inside the class where it is genuinely defined. So just start with abwhich is some function ins- say, convert is somehow to a power series, get the result, and possibly come back. But why do we need such a complication, why is the inputbnot directly in thePowerSeriesRingofQQ?!