Dear Researchers,

sorry If I ask a simple question, but this night I have no idea to resolv
this question. I have a data.frame (just a simple example)


mydata <- data.frame(id=c(1,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,5),
H=c(1,30,43,67,33,78,90,45,4,8,34,3,82,94,12,15,62,89,3,56,96,3),
limit=c(4,4,4,4,4,3,3,3,3,6,6,6,6,7,7,7,7,8,8,8,8,8))


i wish to select by "id" the row with "H" value >= of the boulde of limit (H
>= limit*2) to have a new data.frame

mydata
   id  H limit limit2
2   1 30     4      8
3   1 43     4      8
4   1 67     4      8
5   1 33     4      8
6   2 78     3      6
7   2 90     3      6
8   2 45     3      6
11  3 34     6     12
13  3 82     6     12
14  4 94     7     14
16  4 15     7     14
17  4 62     7     14
18  5 89     8     16
20  5 56     8     16
21  5 96     8     16


thanks and sorry for desturb with easy question

gianni

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