Entering edit mode
My perspective on this is that a parsing package should return
information
in the very basic R data structures (lists, vectors, matrices) and not
involve any classes from downstream analysis packages. If we (the
parsing
package) start to support downstream classes, we will have to depend
on a
(possible large) number of packages.
We (illuminaio) should consider having a convenience function which
reads a
set of IDAT files into a matrix of intensities; this would be very
helpful
to many 'users'. The function could check that all IDAT files are of
the
same type, they all exists, do path expansion etc etc. Then it would
be up
to a downstream analysis package to take this matrix and wrap their
own
class structure around it. This should be easy to write (but of
course it
will take some development time). We would even be able to make the
parsing faster by only parsing part of the file (well, that depends on
whether it is an encrypted or unencrypted IDAT).
Sean, for control probes there is (afaik) no information in the IDAT
files;
it is just a set of intensities.
Best,
Kasper
On Thu, Nov 28, 2013 at 11:30 AM, Mike Smith <grimbough@gmail.com>
wrote:
> Hi Gordon,
>
> Matt has kindly already sent me a copy of his script for creating
the EList
> object. Combined with Sean's code for generating a LumiBatch and
the
> script I'm putting together for beadarray I think we have most of
the
> downstream expression analysis packages covered. My initial hope
was that
> individual packages would import illuminaio (I like the elegance of
having
> a single function in the library) and modify their data input
routines to
> take both the text and IDAT formats. I'll discuss it with Kasper as
> illuminaio is ultimately his package.
>
> Cheers,
>
> Mike
>
>
> On 28 November 2013 02:20, Gordon K Smyth <smyth@wehi.edu.au> wrote:
>
> > Dear Sean and Mike,
> >
> > We (actually Matt Ritchie) have written a nice little function
that uses
> > readIDAT() to read the IDAT files and assembles the pieces into a
data
> > object ready for limma analysis. The output is an EList object,
but it
> > could be an ExpressionSet instead.
> >
> > It has been suggested that this function could be added to the
limma
> > package, but I wondered whether the illuminaio package would be
the best
> > home.
> >
> > What would you like us to do?
> >
> > Best wishes
> > Gordon
> >
> > Date: Tue, 26 Nov 2013 09:33:17 -0500
> >> From: Sean Davis <sdavis2@mail.nih.gov>
> >> To: "bioconductor@r-project.org" <bioconductor@r-project.org>
> >> Subject: [BioC] Illumina Expression analysis from iDAT files
> >>
> >> Hi, all.
> >>
> >> I have a set of iDAT files from illumina expression arrays and
have been
> >> looking around for a workflow that begins with the iDAT files.
> Illuminaio
> >> can read them and beadarray and lumi packages (to name a couple)
can
> deal
> >> with illumina data normalization and processing, but I didn't
find a
> >> bridge
> >> between the illuminaio output and further processing. I very
well may
> >> have
> >> missed something, but I thought I would check.
> >>
> >> Thanks,
> >> Sean
> >>
> >
> >
______________________________________________________________________
> > The information in this email is confidential and
inte...{{dropped:18}}
>
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