> From: Gabriel Dos Reis <[EMAIL PROTECTED]> >> Paul Schlie <[EMAIL PROTECTED]> writes: > | > From: Gabriel Dos Reis <[EMAIL PROTECTED]> > | > |Paul Schlie <[EMAIL PROTECTED]> writes: > | > | Thank you. In essence, I've intentionally defined the question of x^y's > | > | value about x=y->0 as a constrained "bivariate" function, to where only > | > | the direction, not the relative rate of the argument's paths are > | > | ambiguous, as I believe that when the numerical representation system > | > | has no provision to express their relative rates of convergence, they > | > | should be assumed to be equivalent; > | > > | > You're seriously mistaken. In lack of any further knowledge, one should > | > not assume anything particular. Which is reflected in LIA-2's rationale. > | > You just don't know anything about the rate of the arguments. > | > | I guess I'd simply contend that the value of a function about any point > | in the absents of further formal constraints should be assumed to represent > | it's static value about that point i.e. lim{|v|->1/inf) f(x+v, y+v, ...) > > That is menaingless. > > A floating point system is a projection on a discrete base set, as a > consequence when you compute a value, you almost always don't get an > element in that set: You need to make projection. Consistency predictable
- What is meaningless? lim{|v|->1/inf) f(x+v, y+v, ...) isn't meant to necessarily be literally computed, but only abstractly express a limit about a uniformly converging point, as a proposed generally useful and predictable basis of a functions value definition; as opposed to assuming that if a function's arguments about some point are subject to some very specific but non-specifiable set of constraints which yield an ambiguity, it's value is deemed generally ambiguous, and appropriate to return a Nan result for the remaining infinite-1 set of conditions where it's otherwise reasonably well defined at that limit (which seems counterproductive). > | And reserve the obligation for applications requiring the calculation > | of formally parameterized multi-variate functions at boundary limits to > | themselves; rather than burdening either uses of such functions with > | arguably less useful Nan results. > > But that is nnot - We simply disagree. As I perceive Nan run-time results to be about as useful as an "I don't know" response to a question which demands an answer, even if only the most typically useful one. (Where if a more accurate situation specific results are required, I perceive it as the application's responsibility to provision, thereby not burdening either with run-time "I don't know" responses. > | But understand, that regardless of my own opinion; it's likely more > | important that a function produces predicable results, regardless of > | their usefulness on occasion. (which is the obligation of the committees > | to hopefully decide well)