Hello, as you can imagine, I am new to R. I have a problem plotting the results of my svm classification of microarray data. So, I have a matrix of 30 rows (samples) and 306 columns (significant genes). I transform the matrix to a data frame in order to do the classification. My code is: data<-t(significantGenes) labels<-gl(2,20,30) data<-data.frame(data) svm.cross <- svm(data, labels, type="C-classification", kernel="polynomial", degree=5, gamma=0.5, coef0=1, cross=10) This code works great! But when I try to plot the results (using many different ways listed online), I get the following error: "Error in terms.default(x) : no terms component nor attribute" Here is SOME of the ways I've tried to plot the result: plot(svm.cross, data, formula = V1~V2) plot(svm.cross, data, formula = V1~V2, slice = list(V1=2,V2=2)) plot(svm.cross, data, formula = data[,1]~data[,2]) and plot(svm.cross, data,formula=data["V1"]~data[V2]) with error: "Error in model.frame.default(formula, data) : invalid type (list) for variable 'data["V1"]'" Note that str(data) gives: 'data.frame': 30 obs. of 306 variables: $ V1 : num 10.8 10.3 12.5 12.7 11.7 ... $ V2 : num 9.5 10.34 11.25 11.56 9.74 ... $ V3 : num 9.36 11.67 10.52 11.57 10.25 ... $ V4 : num 9.25 8.52 10.61 11.21 9.84 ... etc. Thank you so much for your response. Kind regards, Despina [[alternative HTML version deleted]]