[BioC] LIMMA - unconnected experiments

Gordon K Smyth smyth at wehi.EDU.AU
Sat Feb 26 14:55:21 CET 2005


> Date: Fri, 25 Feb 2005 17:34:18 -0800
> From: Federico Scossa <fscossa at pw.usda.gov>
> Subject: [BioC] LIMMA - unconnected experiments
> To: bioconductor at stat.math.ethz.ch
>
> Hi all,
> I have a couple of questions about unconnected experiments:
>
> - I understand that a pre-requisite for single channel analysis of two
> colour data is Aquantile normalization between arrays... but shall I
> normalize WITHIN arrays, too?

You need to do some sort of separate channel normalization, Aquantile is one possibility. 
Aquantile normalization between arrays is intended to be used in conjunction with loess
normalization within arrays.  Loess normlizes the M-values, Aquantile the A-values.  Between them
you have normalized the absolute intensities.

> - is there a way to export the normalized single-channel intensities from
> LIMMA?

There are naturally many ways, but none are provided as built-in commands.  Conversion is provided
to exprSet objects.  Other than that, I don't have any plans to implement export methods.

Gordon

> thank you, any help appreciated.
>
> Federico



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