[BioC] Error in ebayes: No residual degrees of freedom in linear model fits
huber at ebi.ac.uk
Tue May 26 23:38:26 CEST 2009
Lucas Santana dos Santos ha scritto:
> Dear Group,
> I am trying to find differential expressed genes using Limma, however I
> got the following error when I try eBayes:
> Error in ebayes(fit = fit, proportion = proportion, stdev.coef.lim =
> stdev.coef.lim) :
> No residual degrees of freedom in linear model fits
> My dataset consists of 8 arrays from 8 different cell lines. I have no
> I just want to see which genes are differentially expressed between
> these cell lines.
> I am wondering if I need more than one array per cell line in order to
> make this work.
> Maybe eBayes need replicates to generate variability. Does it make sense?
> A similar post already exists:
> Thank you,
without replication, you will not be able to use limma / eBayes to get
statistical measures of significance of differential expression.
What you can do is:
- look at the width of distribution of (log-)intensities and eye-ball
the large-looking ones, or
- decide on a more specific question to ask from your data, or
- ask the people who produced the data to provide replication.
Wolfgang Huber, EMBL, http://www.ebi.ac.uk/huber
More information about the Bioconductor