What does the title of your question have to do with the question itself?

Agree with other comment - In the future please provide a descriptive title relating to the issue you are having.

The above code from the documentation doesn't work for you as you have miscopied data.frame(sampleData) which should be data(sampleData) . I could run the following example in the man documentation with no issue:

   library(CNTools)
   data("sampleData")
   # take a subset of the data for speed
   seg <- CNSeg(sampleData[which(is.element(sampleData[, "ID"], 
       sample(unique(sampleData[, "ID"]), 10))), ])
   rsBypair <- getRS(seg, by = "pair", imput = FALSE, XY = FALSE, what = "mean")
   rsBypair

Perhaps the CNTools maintainer may be able to provide more detail, but according to the vignette (accessible for this package with vignette("HowTo")

 geneMap: a matrix containing five columns named as chrom - the chromosome a
gene is on, start - start location of a gene, end - ending location of a gene, geneid -
entrez gene id, and genename - official gene symbol. geneInfo is required when by
== ”gene”. An example of geneInfo can be found by loading the geneInfo object
using data(”geneInfo”). The object was built for human genes based on build 36.

So before running the above getRS command utilizing geneMap argument, the following is shown in the vignette:

data("geneInfo")
geneInfo <- geneInfo[sample(1:nrow(geneInfo), 2000), ]
rdByGene <- getRS(cnseg, by = "gene", imput = FALSE, XY = FALSE, geneMap = geneInfo)

Hope this helps.