Hi Gilles, 2012/6/2 Luc Maisonobe <luc.maison...@free.fr>: > Le 02/06/2012 01:55, Gilles Sadowski a écrit : >> Hello. > > Hi Gilles, > >> >> Do you know the rationale behind the (very) small values for >> DEFAULT_RELATIVE_THRESHOLD (set to 100 * Precision.EPSILON) >> DEFAULT_ABSOLUTE_THRESHOLD (set to 100 * Precision.SAFE_MIN) >> in "AbstractConvergenceChecker"? >> [I created this class as part of a refactoring, but the values were carried >> over from whatever class contained that functionality before.] >> >> With those values, the "GaussNewtonOptimizer" fails to find the solution but >> if one changes the threshold to either >> 1e3 * Precision.EPSILON (for the relative threshold) >> or >> 1e281 * Precision.SAFE_MIN (for the absolute threshold) >> the solution is found in 4 evaluations! >> >> As I wrote on the user ML, the thresholds were too stringent. >> Are the current values really suitable as defaults (in other part of the >> library, similar defaults are much larger)? >> [I even think that there shouldn't be any defaults, so that users are >> actually aware that the thresholds are problem-dependent and sometimes even >> optimizer-dependent. My preference would thus be to deprecate the default >> constructor in all the checker classes.] > > I think I wrote the initial classes, and I picked the values from a > domain-specific case. So from a general point of view, these values are > probably worthless. > > OK for deprecating in 3.1 and suppressing the values in 4.0. > I'm also +1 for this change. Sébastien
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