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

Wed Mar 6 17:06:17 CET 2013

Hi,
No problem.
V1<-rep(c(rep(111,5),rep(222,5),rep(333,5)),2)
 length(V1)
#[1] 30

 V2<- c(1:30) #should be the same length as V1
Tem1<- cbind(V1,V2)
Tem2<-Tem1[1:20,]

Tem1[!Tem1[,2]%in%Tem2[,2],]
 #      V1 V2
 #[1,] 222 21
 #[2,] 222 22
 #[3,] 222 23
 #[4,] 222 24
 #[5,] 222 25
 #[6,] 333 26
 #[7,] 333 27
 #[8,] 333 28
 #[9,] 333 29
#[10,] 333 30

#or
subset(Tem1,!V2%in% Tem2[,2])
#or
 Tem1[is.na(match(Tem1[,2],Tem2[,2])),]
 #      V1 V2
 #[1,] 222 21
 #[2,] 222 22
 #[3,] 222 23
 #[4,] 222 24
 #[5,] 222 25
 #[6,] 333 26
 #[7,] 333 27
 #[8,] 333 28
 #[9,] 333 29
#[10,] 333 30
A.K.

________________________________
From: HJ YAN <yhj204 at googlemail.com>
To: arun <smartpink111 at yahoo.com> 
Sent: Wednesday, March 6, 2013 10:33 AM
Subject: Re: [R] How to combine conditional argument and logical argument in R to create subset of data...

Thank you SO MUCH Arun!!! 

That's brilliant-- I've learnt some very useful new R command now, e.g. 'do.call' and 'split'. And I see where my code went wrong now. 

 I do appreciate greatly for your prompt reply.

Also, I wonder if there exist a package can find difference between two data frames, e.g. one is a subset of the other? e.g. 

 V1<-rep(c(rep(111,5),rep(222,5),rep(333,5)),2)
 V2<-c(1:23)
Tem1<-cbind(V1,V2)

Tem2<-Tem1[1:20,]

How do I get outcome like 

[21,] 333 21
[22,] 333 22
[23,] 333 23

P.S. I used 'setdiff' before, but seems it only works for vectors but not for dataframe??

Sorry for so many questions today, as I'm coding for a work deadline tonight.

Many thanks!
Cheers
HJ

On Wed, Mar 6, 2013 at 1:55 PM, arun <smartpink111 at yahoo.com> wrote:

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]]
>>
>>______________________________________________
>>R-help at r-project.org mailing list
>>https://stat.ethz.ch/mailman/listinfo/r-help
>>PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>>and provide commented, minimal, self-contained, reproducible code.
>>
>>     
>