Subset with unique cases, based on multiple columns

Question

I\'d like to subset a dataframe to include only rows that have unique combinations of three columns. My situation is similar to the one presented in this question, but I\'d

Answer 1

A non-elegant but functional way is to paste the entries of a given row together and find which are unique (or non-unique) rows, something like:

df.vector=apply(df,1,FUN=function(x) {paste(x,collapse="")})
df.table=table(df.vector)

then get the indexes of the duplicates with something like:

which(df.vector%in%names(which(df.table>1)))