[R] How to find the min and max of two variables in a data frame

[kxk]

I have two variables in a data frame, I want to generate two additional
variables. For every observations (i.e. every row), I want the first new
variable 'min' to carry the minimum of the two existing variables, and I
want the second new variable 'max' to carry the maximum of the two existing
variables.  I then want to sort the data frame by min and max, and delete
duplicated rows if both rows has the same min and same max. 

I am new to R so not sure how to fix my code.  Here is my attempt and it is
not working.  Thanks!

edge_dir$min=edge_dir[if (edge_dir$cid_dir1 < edeg_dir$cid_dir2)
edge_dir$cid_dir1 else edge_dir$cid_dir2]
edge_dir$max=edge_dir[if (edge_dir$cid_dir1 > edeg_dir$cid_dir2)
edge_dir$cid_dir1 else edge_dir$cid_dir2]

-- 
View this message in context: http://www.nabble.com/How-to-find-the-min-and-max-of-two-variables-in-a-data-frame-tp24638856p24638856.html
Sent from the R help mailing list archive at Nabble.com.