i want to get the detail information at the gene level...so i have use aCGH pakage and i have created the acgh object.. i want to get the graph which show me the loss and gain . So i have use plot genome function ..plotGenome(ex.acgh,samples =c("OC1405","OC1663"), naut = 22,Y = TRUE, X= TRUE,data = log2.ratios(ex.acgh),yScale = c(-2,2),samplenames = sample.names(ex.acgh),ylb ="Log2Ratio") .. i am getting this error..

Error in order(datainfo$Chrom, datainfo$kb) : argument 1 is not a vector.

 In the synatx --- plotGenome(aCGH.obj, samples = 1:num.samples(aCGH.obj), naut = 22, Y = TRUE, X = TRUE, data = log2.ratios(aCGH.obj),chrominfo = human.chrom.info.Jul03,
   yScale = c(-2, 2), samplenames = sample.names(aCGH.obj), ylb = "Log2Ratio").

 what value we have to give in sample variable..