Dear R-users I would like to read a txt file as list, to select rows and columns, and to create barplots. (1) selection of parameter site and part: ok (2) read txt file as list: problem with (1) as there are NA's (the lines not selected) (3) barplot: 5 different groups of bars (the selected columns H5,H8, S5,S8, C8). In each group 4 different bars (parameter diversity) --> error in -0.01*height: non-numeric argument to binary operator PROBLEM As (2) gives NULL, I think that there is a mistake in my r-script with the vector/list function. Thanks Sibylle --