Читать книгу The Big R-Book - Philippe J. S. De Brouwer - Страница 104

R will allow the use of short-cuts, provided that they are unique. For example, in the data-frame data_test there is a column Name. There are no other columns whose name start with the letter “N”; hence. this one letter is enough to address this column.

short-cut

data_test$N ## [1] Piotr Pawel Paula Lisa Laura ## Levels: Laura Lisa Paula Pawel Piotr