Hi Bogdan, If you mean "How can I verify that "B1:B2:B3" is paired with all of the values 2, 4 and 5"
apply(table(df$col_names,df$CT),1,all) and if you mean "How can I verify that "B1:B2:B3" is paired with at least one of the values 2, 4 and 5" apply(table(df$col_names,df$CT),1,any) Jim Hi Jim, yes, thank you, that is the desired output. one more question please : after using the dataframe : df <- data.frame (row_names = c("B4:B5:B6", "B7:B8:B9", "D4:D5:D6", "D10:D11:D12", "D10:D11:D12", "E10:E11:E12", "A1:A2:A3", "B10:B11:B12"), col_names = c ("B1:B2:B3","B1:B2:B3","H4:H5:H6","F10:F11:F12","H1:H2:H3","G7:G8:G9","D1:D2:D3","B1:B2:B3"), CT = c(5,2,2,2,2,2,4,4) ) and : table(df$row_names,df$CT) table(df$col_names,df$CT) how could I quickly verify that "B1:B2:B3" (for example) hits the CT values of 2,4,5 at least one time ? an example is in table(df$col_names,df$CT) ? thank you very much, -- bogdan ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.