On Wed, Apr 23, 2008 at 1:48 PM, Gary Furnish wrote: > ... > Right now, most functionality of the sage.calculus module is dictated > strictly by how maxima is designed. As we move to our own internal > representation, this obviously will not be sufficient.
It is not immediately obvious to me that this is not sufficient. To decide it might first be necessary to define more carefully exactly what you want to be able to do in Sage. > I'd be interested in hearing which features of FriCAS/OpenAxiom has > that might be useful in more detail. Here is a very short and personally biased summary: I think a big difference between Maxima and Sage is that Maxima is *untyped* or rather, there is really only one type of object in Maxima - an expression - while Sage attempts to treat objects as belonging to different mathematical categories. For example: a Polynomial is built over some coefficient Ring, etc. Sage is like Axiom in this respect. On the other hand Axiom has a domain called 'Expression' which fits into the overall mathematical category struture in a well-defined manner, i.e. it consists of a formal extension of the rational functions (Fraction Polynomial). The Expression domain is very different from simply being a "symbolic expression" in the sense used in Maxima. Axiom has another domain called InputForm which is much more like Maxima's symbolic expressions but in Axiom it is used only for the internal representation of input to the interpreter. Very little expression manipulation occurs in Axiom at this level although some people have argued that Axiom should have better support of doing this sort of thing. Closely related to this is another set of domains in Axiom related to pattern matching in Expression and other less highly structured symbolic domains. > My main technical concerns are that anything interacting > through a pexpect interface is going to be slow and will not > interact with Sage's internal coercion system (aside from the > fact that adding another dependency to the standard core > increases code complexity for symbolics dramatically). Could you explain more about why you say this will not (can not?) interact with Sage's coercion system? > I downloaded FriCAS to try to investigate, but I couldn't > find a good introduction to the high level structure of the > FriCAS code (at the file level). Does such a thing exist? > Do you really mean "structure of the code at the file level" or do you want something more conceptual? For example: Have you looked at the Axiom book (a little over 1000 pages). Chapters 11, 12 and 13 describe the tools used to build the Axiom library. Have you tried hyperdoc to navigate the mathematical structure? If you really mean "at the file level", the files that you will probably care most about are those found in the src/algebra directory. Regards, Bill Page. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ open-axiom-devel mailing list open-axiom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open-axiom-devel
