[R] How to combine conditional argument and logical argument in R to create subset of data...

[arun]

Hi,
You can also try this:
 Tem3<- list()
 for(i in unique(Tem1[,1])) {
 Tem3[[i]]<- subset(Tem1,Tem1[,1]==i)
 Tem4<- do.call(rbind,Tem3)
 }
head(Tem4)
#      V1 V2
#[1,] 111  1
#[2,] 111  2
#[3,] 111  3
#[4,] 111  4
#[5,] 111 13
#[6,] 111 14


#or
Tem3<-c(NA,NA)
 for(i in unique(Tem1[,1])) {
 Tem2<- subset(Tem1, Tem1[,1]==i)
 Tem3<- rbind(Tem3,Tem2)
 Tem5<- Tem3[-1,]
 }
head(Tem5)
#  V1 V2
# 111  1
# 111  2
# 111  3
# 111  4
# 111 13
# 111 14

A.K.


________________________________
From: HJ YAN <yhj204 at googlemail.com>
To: arun <smartpink111 at yahoo.com> 
Cc: r-help at r-project.org 
Sent: Wednesday, March 6, 2013 8:24 AM
Subject: Re: [R] How to combine conditional argument and logical argument in R to create subset of data...


Hi Arun


Thank you so much for the help, that's really helpful!!

Also I have a quick question about the code below where I can not see why it doesn't work...

I know the I shou

V1<-c(rep(111,4),rep(222,4),rep(333,4),rep(111,4),rep(222,4),rep(333,3))
V2<-c(1:23)
Tem1<-cbind(V1,V2)


So Tem 1 looks like...
> Tem1
       V1 V2
 [1,] 111  1
 [2,] 111  2
 [3,] 111  3
 [4,] 111  4
 [5,] 222  5
 [6,] 222  6
 [7,] 222  7
 [8,] 222  8
 [9,] 333  9
[10,] 333 10
[11,] 333 11
[12,] 333 12
[13,] 111 13
[14,] 111 14
[15,] 111 15
[16,] 111 16
[17,] 222 17
[18,] 222 18
[19,] 222 19
[20,] 222 20
[21,] 333 21
[22,] 333 22
[23,] 333 23

I would like the outcome to be...

      V1 V2

     111  1
     111  2
     111  3
     111  4
     111 13
     111 14
     111 15
     111 16
     222  5
     222  6
     222  7
     222  8
     222 17
     222 18
     222 19
     222 20
     333  9
     333 10
     333 11
     333 12
     333 21
     333 22
     333 23


So I tried code as below 
------------------------------------------
Tem3<-c(NA,NA)
for(i in length(unique(Tem1[,1]))){
Tem2<-subset(Tem1,Tem1[,1]==unique(Tem1[,1])[i])
Tem3<-rbind(Tem3,Tem2)
Tem3
}
Tem4<-Tem3[-1,]
---------------------------------------

And only get this...


 V1 V2
 333  9
 333 10
 333 11
 333 12
 333 21
 333 22
 333 23


I tried to run the code step by step, e.g. letting i=1, then i=2, then i= 3, and updating my Tem3, I did get what I wanted, but wondered why in the loop above it did not work...??


Many thanks in advance!

HJ















On Wed, Mar 6, 2013 at 4:36 AM, arun <smartpink111 at yahoo.com> wrote:

Hi,
>
> b[b[,4]>15 & (b[,1]>4|is.na(b[,1])) & (b[,2]>4|is.na(b[,2])),]
> #    [,1] [,2] [,3] [,4] [,5]
>#[1,]    6   NA   NA   16   20
>#[2,]   NA    5   NA   17   21
>A.K.
>
>
>
>----- Original Message -----
>From: HJ YAN <yhj204 at googlemail.com>
>To: r-help at r-project.org
>Cc:
>Sent: Tuesday, March 5, 2013 9:33 PM
>Subject: [R] How to combine conditional argument and logical argument in R to create subset of data...
>
>Dear R user
>
>I have data created using code below
>
>b<-matrix(2:21,nrow=4)
>b[,1:3]=NA
>b[4,2]=5
>b[3,1]=6
>
>Now the data is
>
>> b
>         [,1]  [,2]   [,3]  [,4]  [,5]
>[1,]   NA   NA   NA   14   18
>[2,]   NA   NA   NA   15   19
>[3,]      6   NA   NA   16   20
>[4,]   NA    5     NA    17   21
>
>
>I want to keep data in column 4 greater than 15 and the value in column 1 &
>2 either greater than 4 or is 'NA'. So I would like to have
>my outcome as below...
>
>[3,]   6   NA NA 16 20
>[4,] NA 5 NA 17 21
>
>I thought something like the code below gonna to work but it only returns
>the last row,e.g "NA 5 NA 17 21". ...
>
>bb<-b[which( (b[,2]>4 | b[,2]==NA) & (b[,1]>4 | b[,1]==NA) & b[,4]>15) ,])
>
>
>Please could anyone help?
>
>Many thanks in advance
>
>HJ
>
>    [[alternative HTML version deleted]]
>
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>
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