Thank you for your insightful comment.
Dear all,
I tried to use below code to normalize my data before using combat to deal with batch effects:
- library(affy)
- norm <- ReadAffy()
- norm.rma <-rma(norm)
Unluckily, my data include 3 data sets, 2 Affymetrix Human Genome U133 Plus 2.0 Array and 1 Affymetrix Human Gene 1.0 ST Array. I received this error message "Error in affyio::read_abatch(filenames, rm.mask, rm.outliers, rm.extra,: Cel file D:////batchdemo/GSMxxxx.CEL.gz does not seem to have the correct dimensions".
I tried to use dchip instead but again, I failed. I even couldn't input the data to dchip.
Any advice and suggestions will be greatly appreciated.
Thank you.
2 answers
Using arrays from different platforms is not as simple as just reading them in and normalising them together. You'll need to read in each dataset individually, normalise, use only probes that are on both platforms (check out nuIDs for this), then account for the variation across platforms in Limma (use an additive model), when performing differential gene expression. This is not a trivial task.
hii i am trying to normalize microarray data from two different platform. when i normalize GSE2361 indiviually using code: library(affy) norm <- ReadAffy() norm.rma <-rma(norm) Error in exprs(object)[index, , drop = FALSE] : subscript out of bounds give me suggestion.
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