Hi all. I'm willing to invest some of my time to understand if I can be able to do a step ahead with symbolic functions.
How are special symbolic functions supposed to be defined? I am willing to experiment with delta of dirac function. This has some special properties (see http://en.wikipedia.org/wiki/Dirac_delta_function ), some of them are really useful but I don't know how to define them in a CAS like maxima or SAGE. I'm aware that it is already present in maxima, even though I don't think it is recognized by SAGE. I am wondering whether a viable approach could be to add to calculus.py a section similar to the one of Function_gamma, so that SAGE simply interfaces to maxima. I don't know if this is useful or not. Otherwise, I would be interested in knowing if this could be done with the new symbolic package. Burcin proved to be very helpful in showing me a simple way to define delta function by means of its values and he assigned it as being the derivative of heaviside function (defined in a sort of piecewise function): sage: heaviside(x).diff(x) dirac(x) is there a way to implement the other properties? I am willing to know if is there any documentation about that, because I am not able to find that! I am willing to learn something about pynac, but please feel free to discourage me if you think it is too far away from being ready. Is there any integration or derivation capability ready? Is it possible to start testing it using maxima's integration capabilities? (I don't think so...) I was browsing the todo page ( http://wiki.sagemath.org/symbolics/pynac_todo ) but it seems that many action items went away... are they already accomplished? (what about the TODO showed in http://wiki.sagemath.org/symbolics ?) I have to say I find the actual SAGE documentation seems pretty hard to browse, but could be my fault. Yesterday I lost half an hour looking for a "numerical solve" or something like that, before finding the "find_roots" function. Today, I spent half an hour looking for "differential equation solve" with no success. I am sure I could do some DE solution in the past (something with maxima, something with SymPy, I think, all through SAGE), but I think that I found the way to do it pretty easily browsing the old reference manual... Thanks a lot Maurizio PS: delta of dirac is already in SymPy ( http://code.google.com/p/sympy/issues/detail?id=672&can=1&q=dirac ), am I correct in thinking that the current function definition is different than SAGE? In this case, I assume this could be some good reading, but not necessarily a source of inspiration, right? --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
