R: remove rows with same in all columns

Question

Input file:

y <- read.table(textConnection('
   c1   c2   c3
1  a    b    -1
2  a    b    -1
3  a    c    1
4  a    b    1
5  a    b    -1
'), header=TRUE)

thus, y is

  c1 c2 c3
1  a  b -1
2  a  b -1
3  a  c  1
4  a  b  1
5  a  b  -1

the output file would be:

  c1 c2 c3
1  a  b -1
3  a  c  1
4  a  b  1

How to remove multiple or duplicate rows with same entry in all columns?

Answer 1

Try unique(y)

> unique(y)
  c1 c2 c3
1  a  b -1
3  a  c  1
4  a  b  1

Answer 2

?unique. Watch out for floating point variables though...