Hi.

On Tue, Oct 28, 2008 at 3:52 PM, Venkat <[EMAIL PROTECTED]> wrote:
>
> Thanks Henrik.
>
>> The QuantileNormalization class/method works for any Affymetrix chip type.
>>
>> There are many different ways to pre-process data out there and the
>> two vignettes show to different ways.
>>
>> I should really put up a CRMA (v1) vignette illustrating the exact
>> steps in the Bengtsson et al. (2008) paper or CRMA preprocessing (our
>> preferred method) of 500K (and before), but short of time...  Although
>> developed for 500K (before GWS5/6 came out), the CRMA model (with some
>> modifications) actually applies to GWS5/GWS6 arrays too.  If replacing
>> AvgCnPlm with RlmCnPlm in the GWS6 vignette, you actually have CRMA.
>
> As a followup is it redundant to do
>
>  qn <- QuantileNormalization(csC)
>  csN <- process(qn, verbose=verbose)
>
> prior to
>
>  plm <- RmaCnPlm(csN, mergeStrands=TRUE, combineAlleles=FALSE, shift=
> +300)
>  fit(plm, verbose=verbose)
>
> i.e. will the plm fit from RmaCnPlm with and without the
> QuantileNormalization step be the same.

No.

I see your confusion: The "Rma" part of "RmaCnPlm" is referring to the
RMA-style probe summarization (=the log-additive model) and not any of
the other parts of the RMA model.  Thus, it does not include QN.  We
chosed to call it Rma*Plm to show the origin of the probe-level model
(PLM).  LogAdditivePlm was discussed but we though it was not specific
enough.  We also have dChip's Mbei*Plm, and ours Affine*Plm (also a
multiplicative model related to MBEI) and Avg*Plm.

>
> And if so does  RmaCnPlm  have a  subsetToAvg  argument.

So, no, because it fit the log-additive model to each unit separately
(across arrays).

Hope this clarifies a few things

Henrik

>
> Thanks,
> Venkat
>
> >
>

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