Re: Cell arrays of strings in "sort" and "unique"

[Alois Schloegl]

David Bateman wrote:

> According to Quentin Spencer <address@hidden> (on 09/15/04):
>  
>
> > Output from MATLAB R14:
> >
> >
> >
> >    
> >
> > > > x = [Inf, NaN, -Inf, 3, 2, 1];
> > > > [a, ai] = sort (x, 'ascend')
> > > >        
> > a =
> >
> > -Inf     1     2     3   Inf   NaN
> >
> >
> > ai =
> >
> >    3     6     5     4     1     2
> >
> >    
> >
> > > > [a, ai] = sort (x, 'descend')
> > > >        
> > a =
> >
> >  NaN   Inf     3     2     1  -Inf
> >
> >
> > ai =
> >
> >    2     1     4     5     6     3
> >    
>
>
> Now this isn't what I would have expected. I'd assumed that the NaN's
> were always sorted to the end. It seems that matlab always does an
> ascending sort and then a flip(lr|ud) or whatever... It might in fact
> be faster this way, but the advantage of always sorting the NaN's
> to the end would be that it is easier to drop them...
>
> For compatiability we shoudl probably do the same thing...
>  

In this case, compatibility is not a "must". The result might differ 
already in the next version of matlab.
If the position of NaN is important, its recommended doing explicit 
checks for NaN's - and if only for the sake of readibility of the code.

- just my 2c -


 Alois