Dear all,

Thanks for reading.  I have tried to follow this tutorial http://bioinformatics.knowledgeblog.org/2011/06/20/analysing-microarray-data-in-bioconductor/

however, when I arrive to the point of annotating the results with associated gene symbols I get this error

> gene.symbols <- getSYMBOL(probeset.list$ID, "hgu133plus2")
Error in unlist(lookUp(x, data, "SYMBOL")) : 
  error in evaluating the argument 'x' in selecting a method for function 'unlist': Error in lookUp(x, data, "SYMBOL") : No keys provided

The same error has happened to me with other examples (different arrays), so I do not know how to sort it out. Anybody has any idea? Thanks very much,

Regards

IOM

The new and improved ways of doing these types of lookup/cross-refs is to use select.

This question pops up quite a bit, so if you search for something like "convert probeset symbol" on this site, you should find a few answers already, such as:

Take a look at some of the "Similar Posts" listed on the right of this page for this question, ie:

• Question about converting rownames of an expression dataset to their corresponding gene symbols
• Annotating the results with associated gene symbols

Thanks Steve,

I will do what you say. Cheers

IOM