How to filter for unique combination of columns from an R dataframe

r filtering unique
megv picture megv · Dec 2, 2011 · Viewed 50.3k times · Source

I am trying to filter out the duplicates of a subset of columns from a dataframe in R.

I am interested in filtering unique combinations of session, first, and last. The following is what my data looks like

                        session       first     last            city
1  9cf571c8faa67cad2aa9ff41f3a26e38     cat   biddix          fresno
2  e30f853d4e54604fd62858badb68113a   caleb     amos                
3  2ad41134cc285bcc06892fd68a471cd7  daniel  folkers                
4  2ad41134cc285bcc06892fd68a471cd7  daniel  folkers                
5  63a5e839510a647c1ff3b8aed684c2a5 charles   pierce           flint
6  691df47f2df12f14f000f9a17d1cc40e       j    franz prescott+valley
7  691df47f2df12f14f000f9a17d1cc40e       j    franz prescott+valley
8  b3a1476aa37ae4b799495256324a8d3d  carrie mascorro            brea
9  bd9f1404b313415e7e7b8769376d2705    fred  morales       las+vegas
10 b50a610292803dc302f24ae507ea853a  aurora      lee                
11 fb74940e6feb0dc61a1b4d09fcbbcb37  andrew    price       yorkville

Answer

NPE picture NPE · Dec 2, 2011

The following should do it:

unique(df[,c('session','first','last')])

where df is your data frame.

Related questions

Index value for matrix in R?

Is there a function to get an index (row number and column number) for a matrix? Suppose that I have a simple matrix: a <- matrix(1:50, nrow=5) Is there an easy way to get back something like c(3, 5) for …

Read More
Remove rows from dataframe that contains only 0 or just a single 0

I am trying to create a function in R that will allow me to filter my data set based on whether a row contains a single column with a zero in it. Furthermore, some times I only want to remove …

Read More
R get rows based on multiple conditions - use dplyr and reshape2

df <- data.frame( exp=c(1,1,2,2), name=c("gene1", "gene2", "gene1", "gene2"), value=c(1,1,3,-1) ) In trying to get customed to the dplyr and reshape2I stumbled over a "simple" way to select rows based on several conditions. If …

Read More