[sage list added] "Travis E. Oliphant" <[EMAIL PROTECTED]> writes:
> The SAGE people may be interested in this, but I doubt there will more > than a handful of users of these algebraic base classes. SAGE has quite a sophisticated type hierarchy, and a sophisticated set of coercion methods. What is done in SAGE should definitely be consulted, since it is probably the most complex set of mathematical types yet written in python. The SAGE tutorial is at http://www.sagemath.org/doc/html/tut/tut.html and Section 2.2 gives a brief introduction to numbers: http://www.sagemath.org/doc/html/tut/node9.html The SAGE reference manual is at http://www.sagemath.org/doc/html/ref/index.html Chapter 20: http://www.sagemath.org/doc/html/ref/node198.html and nearby chapters are quite relevant for this discussion. > For general purpose Python, I would do something like > > Complex > Rational_Complex > Integer_Complex > Floating_Complex # uses hardware float > Decimal_Complex > Real > Rational > Integer > Floating # uses hardware float > Decimal Note also that double-precision reals are a subset of the rationals, since each double precision real is exactly representable as a rational number, but many rational numbers are not exactly representable as double precision reals. Not sure if this means that reals should be a subclass of the rationals. I believe that in SAGE these relationships aren't expressed using subclassing. Dan --~--~---------~--~----~------------~-------~--~----~ 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://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
