I know typically you download CEL files then run them through something like readaffy and then use RMA normalization.
However, many datasets on GEO do not have the associated raw CEL files. Furthermore downloading multiple CEL files is both long and tedious.
For some of the things i'm doing, normalizing ExpressionSet files directly obtained using GEOquery package would be much faster and preferable.
I was wondering what kind of packages are out there to normalize data that takes expressionset directly as input? Ideally they would have the same normalization techniques such as RMA.
The GEOquery package has getGEOSuppFiles('GSEXXXX') that will do the downloading of raw data for you.
One cannot use full RMA-like normalization without access to probe-level data. Probe-level data is not typically available in the data deposited in GEO, except when the .CEL files are available.