On 16 February 2012 02:29, Alois Schloegl <alois.schlo...@ist.ac.at> wrote: > If you are tired of these nagging warnings, ask the developers of octave > to fix it. And I do not mean turning off the warning on shadowing > functions, but to implement the NaN-skipping behavior within the > existing core functions.
NaN-skipping behaviour is semantically wrong. "NaN" doesn't mean "missing data". It means "you performed an invalid computation". When you performed an invalid computation, any computation that follows from it is also invalid. Numerical nonsense goes in, numerical nonsense should come out. It is of course tempting to use NaN to represent missing data, because, really, what other value would you use? But it's in fact an abuse of floating point operations. If the data type were not floating points, but, say, integers, what value would you use to represent "missing data"? I think it's ok to change the meaning of "NaN" for statistical convenience, but it's not a solution to use it in this way if you're solving a PDE and your step size is wrong and starts producing NaN. - Jordi G. H. ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev
