[R] For loop

[bibek sharma]

Hello user,
I have large data containing  subject id, time and response where
subjects are measured repeatedly. However some time are duplicates. I
only want data with unique time points per id. I mean if time is
repeated, then take only one.
Here is a sample data.

id	time 	res
1	2	0.64
1	3	0.78
1	3	6.5
1	3	4.5
1	4	4
1	5	3.4
2	10	5.7
2	11	5.8
2	11	9.3
2	11	3.4
2	12	3.4
2	13	6.7
3	3	5.6
3	3	3.4
3	4	2.3
3	5	5.6
3	12	9.8
3	10	7
3	24	6
3	16	4

for 1st subject I want this,

id	time 	res
1	2	0.64
1	3	0.78
1	4	4
1	5	3.4
Any suggestions are much appreciated!
Thanks,
Bikek