[EMAIL PROTECTED] wrote:
>> No. You can make one that fits your requirements, though. > > I am struggling to oversee the implications of design choices for inf > behaviour - especially if it comes to comparison with float type inf. > The type in my application contains a gmpy.mpq and a float that is > always kept between -1 and 1 by adding to the mpq on each operation. > I am looking for a robust inf design for this type. (Note: mpq and > float inf do not compare). Infinity, and all its behaviours are well defined in the General Decimal Arithmetic Specification, here at http://www2.hursley.ibm.com/decimal/. You can always pass your float to Decimal through string, and then do there *all* the operations: >>> from decimal import * >>> a = 3.4 >>> b = 1.0e1000 >>> Decimal(str(a)) Decimal("3.4") >>> Decimal(str(b)) Decimal("Infinity") >>> Decimal(str(b)) / 0 Decimal("Infinity") >>> Decimal(str(b)) * 0 Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/lib/python2.5/decimal.py", line 1140, in __mul__ return context._raise_error(InvalidOperation, '(+-)INF * 0') File "/usr/lib/python2.5/decimal.py", line 2325, in _raise_error raise error, explanation decimal.InvalidOperation: (+-)INF * 0 >>> setcontext(ExtendedContext) >>> Decimal(str(b)) * 0 Decimal("NaN") >>> Regards, -- . Facundo . Blog: http://www.taniquetil.com.ar/plog/ PyAr: http://www.python.org/ar/ -- http://mail.python.org/mailman/listinfo/python-list
