Re: RMS Error question

I think it is possible the RMS error to be greater than the max error.

Eg.

X=[2 3 2 3]
Y=[4 4 4 4]

RMS=1.58
Max error=1


Consider that the RMS error is not normalised. Only if the RMS is normalised with the range (divided with Xmax-Xmin) the max error should be lower than the NRMS (normalised RMS).

http://en.wikipedia.org/wiki/Root-mean-square_deviation


Yannos





"Torsten" wrote in message <k6b4dc$of4$1@newscl01ah.mathworks.com>...
> "Yannos M" wrote in message <k6b1hg$fq1$1@newscl01ah.mathworks.com>...
> > Hi,
> >
> > I have two vectors and I'd like to calculate the RMS error. Thus, I used the function
> >
> > r=sqrt(sum((data(:)-estimate(:)).^2)/numel(data));
> >
> > as found here:
> > http://www.mathworks.com/matlabcentral/fileexchange/21383-rmse
> >
> > However, I get the RMS error to be greater than the MAX error! Is this possible?
> >
> > THanks
>
> No, that's not possible. It always holds that
> RMS <= max(abs(data-estimate))
>
> Best wishes
> Torsten.