Hi, The standart error returned by the se.exprs slot are for a given gene, the same on the different arrays. Is it correct ? or there is a bug in the se.exprs slot ? Example : data(Dilution) e <- express(Dilution) se.exprs(e)[1,] se.exprs(e)[1,] return 0.04187569 for all the arrays ... Thanks L. Buffat

On Tue, Nov 19, 2002 at 11:57:07AM +0100, Laurent Buffat wrote: > > Hi, > > The standart error returned by the se.exprs slot are for a given gene, the > same on the different arrays. > Is it correct ? or there is a bug in the se.exprs slot ? > > Example : > > data(Dilution) > e <- express(Dilution) > se.exprs(e)[1,] > > se.exprs(e)[1,] return 0.04187569 for all the arrays ... > > Thanks > > L. Buffat > Dear Laurent, The se.exprs returned by 'express' depends on the method used to summarize the probe intensities by one expression value. The default 'summary' function for 'express' is 'medianpolish' (unlike what is stated in the man pages. This will be fixed shortly), which gives one rough estimate of se for each gene. Apparently this is not a bug (but I might be corrected on this very same list when the West starts the day). Hopin' it helps, Laurent -------------------------------------------------------------- Laurent Gautier CBS, Building 208, DTU PhD. Student DK-2800 Lyngby,Denmark tel: +45 45 25 24 89 http://www.cbs.dtu.dk/laurent