Select unique values with select function in dplyr library

Question

Is it possible to select all unique values from a column of a data frame using select function in dplyr library  Something like  SELECT DISTINCT field1 FROM table1  in SQL notation   Thanks

User · Answer

Just to add to the other answers  if you would prefer to return a vector rather than a dataframe  you have the following options   dplyr  lt  0 7 0  Enclose the dplyr functions in a parentheses and combine it with   syntax    mtcars   gt   distinct cyl   cyl   dplyr    0 7 0  Use the pull verb   mtcars   gt   distinct cyl    gt   pull

User · Answer

In dplyr 0 3 this can be easily achieved using the distinct   method    Here is an example   distinct df   df   gt   distinct field1   You can get a vector of the distinct values with   distinct vector   distinct df field1  You can also select a subset of columns at the same time as you perform the distinct   call  which can be cleaner to look at if you examine the data frame using head tail glimpse    distinct df   df   gt   distinct field1    gt   select field1  distinct vector   distinct df field1

User · Answer

The dplyr select function selects specific columns from a data frame  To return unique values in a particular column of data  you can use the group by function  For example   library dplyr     Fake data set seed 5  dat   data frame x sample 1 10 100  replace TRUE      Return the distinct values of x dat   gt     group by x    gt     summarise         x 1   1 2   2 3   3 4   4 5   5 6   6 7   7 8   8 9   9 10 10   If you want to change the column name you can add the following   dat   gt     group by x    gt     summarise     gt     select unique x x    This both selects column x from among all the columns in the data frame that dplyr returns  and of course there s only one column in this case  and changes its name to unique x   You can also get the unique values directly in base R with unique dat x     If you have multiple variables and want all unique combinations that appear in the data  you can generalize the above code as follows   set seed 5  dat   data frame x sample 1 10 100  replace TRUE                     y sample letters 1 5   100  replace TRUE    dat   gt      group by x y    gt     summarise     gt     select unique x x  unique y y

[r] Select unique values with 'select' function in 'dplyr' library

Examples related to r

Examples related to select

Examples related to unique

Examples related to dplyr