[BioC] Save rma normalization results for later use
Laurent Gautier
laurent at cbs.dtu.dk
Tue Feb 17 14:46:47 CET 2009
To try out quickly, the RefPlus package can be an "off-the-shelf" option.
L.
Wolfgang Huber wrote:
>
> Hi Christian,
>
> there is some subtlety how quantile normalisation deals with ties
> (values on one array that are exactly the same), but I think your real
> problem will be the probset summarisation step, where you need to
> extract, store, and later apply the probe weights in the RMA model.
>
> Henrik Bengtsson recently suggested (on the bioc-devel list):
>
> For the purpose of fitting the RMA-style log-additive model, I'd say
> that Ben [Bolstad]'s robust estimators implemented in preprocessCore are
> much
> better (and more flexible, e.g. support weights) than using median
> polish. See
>
> help("rcModelPLM", package="preprocessCore")
>
>
>
> Best wishes
> Wolfgang
>
> ----------------------------------------------------
> Wolfgang Huber, EMBL-EBI, http://www.ebi.ac.uk/huber
>
>
>
> Ruckert wrote:
>> I have a bunch of 2000 arrays I want to normalize with rma() from affy
>> package. Then from time to time there will be single arrays to be
>> analyzed together with these 2000. To apply the same normalization
>> procedure to the single arrays later I want to split the rma step in
>> its elements.
>>
>> bg.correct(data, method="rma")
>> As it's array wise I think no problem for the single array.
>>
>> normalize(data, method="quantiles")
>> I think here I need to save the mean values for each row to normalize
>> the single array later with this values (I know it's not totally exact
>> but I think acceptable). In my understanding of the quantile
>> normalization the sorted perfect match values should be exactly the
>> same for every sample, but I got differences.
>>
>> So my questions are:
>> 1. How does the last step look to got exactly the same results as with
>> rma()
>> 2. Why the differences in quantile normalization?
>> 3. Is there a better way to handle this task?
>>
>> Any help would be appreciated,
>>
>> Christian
>>
>> _______________________________________________
>> Bioconductor mailing list
>> Bioconductor at stat.math.ethz.ch
>> https://stat.ethz.ch/mailman/listinfo/bioconductor
>> Search the archives:
>> http://news.gmane.org/gmane.science.biology.informatics.conductor
>
>
> --
>
> _______________________________________________
> Bioconductor mailing list
> Bioconductor at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/bioconductor
> Search the archives:
> http://news.gmane.org/gmane.science.biology.informatics.conductor
More information about the Bioconductor
mailing list