rows argument

The rows argument accepts a predicate expression that is used to specify rows to apply formatting. The expression must evaluate to a logical when evaluated in x$table_body. For example, to apply formatting to the age rows pass rows = variable == "age". A vector of row numbers is NOT acceptable.

The x$table_body contains columns that are hidden in the final print of a table that are often useful for defining these expressions; print the table to view all column available.

A couple of things to note when using the rows argument.

1. You can use saved objects to create the predicate argument, e.g. rows = variable == letters[1].

2. The saved object cannot share a name with a column in x$table_body. The reason for this is that in tbl_merge() the columns are renamed, and the renaming process cannot disambiguate the variable column from an external object named variable in the following expression rows = .data$variable == .env$variable.