On Dec 6, 2008, at 1:15 PM, Jason Grout wrote: > > I'd like to add an exponential function to RDF/CDF matrices (and > enhance > the existing exp function for SR matrices) so that: > > sage: A = matrix(SR, [[1,2],[3,4]]) > sage: e^A > > gives the same as > > sage: A.exp() > > (I'd also like this to work for other matrices, like over RDF or CDF, > where the returned matrix would be another RDF/CDF matrix---scipy has > functions that do this). > > However, currently for constants (in sage/functions/constants.py), the > __pow__ function automatically converts the exponent to an SR object, > which fails for a matrix. > > I have not worked with the constants code before. Would there be a > problem with, for the E constant, overriding __pow__ so that if the > object had an "_exp" method, that was called instead of the default > conversion to SR objects?
+1, this was my first though when I started reading your email. I don't think it makes sense for other constants, but for E it certainly does. Also, I'd just call exp (not _exp), making sure that it doesn't introduce a recursive call... > Would that be the proper way to get the above functionality? The goal > is also to get exp(A) to work as well; would I get that for free? Yes. When you do exp(A) it attempts to return A.exp() before doing anything symbolic. - Robert --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
