x and y are nominal variables (strings) which need to be used to access the columns with the name given by the parameter x and y within the dataframe knime.in, that means, your script would read as plot(knime.in[,x], knime.in[,y]); Hope this helps.
x and y are nominal variables (strings) which need to be used to access the columns with the name given by the parameter x and y within the dataframe knime.in, that means, your script would read as plot(knime.in[,x], knime.in[,y]); Hope this helps.