And....one other feature request for Bruce for Athena version 2.3. It would be nice if we could put constraints on each of the fitting variables. This would help prevent fits where the variables quickly spin off into meaningless territory. Of course, implemenation of this feature could get complex given the number of variables to be fit. An easier implemenation of constraints would be a checkbox and a % deviation field that would let
Dave wrote: the variables chosen float within that %deviation.
Ifeffit (and thus Artemis) already has "max" and "min" features that allow you to approximate this. For example, to require S02 to be between 0.60 and 1.00, you can do the following: guess S02p = 0.80 def S02p = max(0.60,min(1.00,S02p)) Admittedly that is a bit awkward, and Bruce could implement it as you suggest in Artemis. My experience is, however, that this does not work very well. A fit which likes to "spin off" tends to pin itself to one of the edges of the allowed range anyway, and then the ifeffit routines for working out uncertainties and correlations lose their ability to figure out what is going on (the fitted parameter can become in some sense meaningless to the fit). So I think if Bruce implements it that it would just be a source of frustration. You could use "restraints" instead, although that raises its own issues of defensibility and how to choose the weighting function. My preference is to find other ways to make the fit conform to the real world, e.g. I include more paths, or more k-weights, or other constraints, or values from a standard... --Scott Calvin Sarah Lawrence College