On 6/13/19 10:51 AM, R Smith wrote: > On 2019/06/13 4:44 PM, Doug Currie wrote: >>> >>> Except by the rules of IEEE (as I understand them) >>> >>> -0.0 < 0.0 is FALSE, so -0.0 is NOT "definitely left of true zero" >>> >> Except that 0.0 is also an approximation to zero, not "true zero." >> >> Consider that 1/-0.0 is -inf whereas 1/0.0 is +int > > > I do not know if this is the result case in any of the programming > languages, but in Mathematical terms that is just not true. > > 1/0.0 --> Undefined, doesn't exist, cannot be computed, Should error > out. Anything returning +Inf or -Inf is plain wrong. > I posit the same holds true for 1/-0.0
Yes, 1.0/0.0 is undefined in the Field of Real numbers, but IEEE isn't the field of Real Numbers. First, as pointed out, it has limited precision, but secondly it have values that are not in the field of Real Numbers, namely NaN and +/-Inf. Note, that with a computer, you need to do SOMETHING when asked for 1.0/0.0, it isn't good to just stop (and traps/exceptions are hard to define for general compution systems), so defining the result is much better than just defining that anything could happen. It could have been defined as just a NaN, but having a special 'error' value for +Inf or -Inf turns out to be very useful in some fields. -- Richard Damon _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
