[R] selecting certain rows from data frame

[Peter Ehlers]

On 2010-12-14 23:57, steven mosher wrote:
> Hi,
> Next time give folks code to produce a toy sample of your problem
>
>   DF<-data.frame(ID=rep(1:5,each=3),Data=rnorm(15),Stuff=seq(1:15))
>    DF
>     ID       Data Stuff
> 1   1  2.0628225     1
> 2   1  0.6599165     2
> 3   1  0.5672595     3
> 4   2 -0.5308823     4
> 5   2 -0.5358471     5
> 6   2 -0.1414992     6
> 7   3 -0.1679643     7
> 8   3  0.9220922     8
> 9   3  0.8863018     9
> 10  4 -0.7255916    10
> 11  4 -1.2446753    11
> 12  4  0.8165567    12
> 13  5  0.0925008    13
> 14  5 -0.8534803    14
> 15  5 -0.6535016    15
>
> # now I want to select rows where ID = 2 or 5
> # Assign DF2 to those elements of DF where the ID variable=2 or 5
>
>   DF2<- DF[which(DF$ID==2 | DF$ID==5), ]

Or use subset():

  DF2 <- subset(DF, ID %in% c(2,5))

Peter Ehlers

>   DF2
>     ID       Data Stuff
> 4   2 -0.5308823     4
> 5   2 -0.5358471     5
> 6   2 -0.1414992     6
> 13  5  0.0925008    13
> 14  5 -0.8534803    14
> 15  5 -0.6535016    15
>
> On Tue, Dec 14, 2010 at 10:10 PM, Hrithik R<rithrr at yahoo.com>  wrote:
>
>> Hi,
>> if I have a dataframe such that
>>
>> ID Time  Earn
>> 1        1        10
>> 1        2        50
>> 1        3        68
>> 2        1        40
>> 2        2        78
>> 2        4       88
>> 3        1        50
>> 3        2        60
>> 3        3        98
>> 4        1        33
>> 4        2        48
>> 4        4       58
>> .....
>> ....
>> .....
>>
>> Now if I have to select the all the rows from the data frame which does not
>> include rows with certain IDs, say for example (prime) ID == 2&  3, how do
>> I do
>> it
>>
>>
>> Thanks
>>
>> Rith
>>