[R] Help

arun smartpink111 at yahoo.com
Sun Apr 28 03:53:44 CEST 2013

If you wanted to delete "T", "C","A", "F" and "Y" and replace "-999.99M" with NA, it is possible, but the result would be stored in a list if 
the number of elements deleted from each of the columns are different.   As you didn't provide any reproducible example, I don't know whether equal number of elements are replaced from each columns or not..

myfiles<- lapply(1:5,function(i) as.data.frame(matrix(sample(c(LETTERS,"-999.99M"),40*i,replace=TRUE),ncol=(40*i)/8),stringsAsFactors=FALSE))
res<-lapply(myfiles,function(x){x[x=="-999.99M"]<-NA;lapply(x,function(y) y[!y%in%c("T","C","A","F","Y")])})
#[1] "M" "X" "U" "X"
#[1] "P" "Z" "S" "R" "Q" "W" "N" "I"
#[1] "K" "S" NA  "M" "G" "G" "Z"
#[1] "O" "M" "G" "G" "B" "X" "M"
#[1] "I" "X" "P" "K" "R" "K"

From: "zilefacelvis at yahoo.com" <zilefacelvis at yahoo.com>
To: arun <smartpink111 at yahoo.com> 
Cc: R help <r-help at r-project.org> 
Sent: Saturday, April 27, 2013 9:41 PM
Subject: Re: Re: [R] Help

Hi A.K,

Thanks for  this great help. I wish to find -999.99M and replace with NA. All others like T, A, F etc should be deleted from the files.

Thanks for much.

------ Original Message ------

From : arun
>To : Zilefac Elvis;
>Cc : R help;
>Sent : 27-04-2013 16:29
>Subject : Re: [R] Help
>HI, "Find 'T','C','A','F' and 'Y', delete them from all the 110 files"
I assume that you meant to replace it with NA. set.seed(28)
myfiles<- lapply(1:5,function(i) as.data.frame(matrix(sample(c(LETTERS,"-999.99M"),40*i,replace=TRUE),ncol=(40*i)/8),stringsAsFactors=FALSE)) myfiles[[1]]
#  V1 V2       V3 V4 V5
#1  A  P        K  O  Y
#2  C  Z        S  M  Y
#3  M  S -999.99M  G  I
#4  X  R        M  G  X
#5  C  Q        G  A  P
#6  U  W        G  B  K
#7  A  N        Z  X  R
#8  X  I        F  M  K res<-lapply(myfiles,function(x) {x1<-unlist(x); x1[x1%in% c("-999.99M","T","C","A","F","Y")]<-NA;as.data.frame(matrix(x1,ncol=ncol(x)),stringsAsFactors=FALSE)}) res[[1]] #   V1 V2   V3   V4   V5
#1    P    K    O  
#2    Z    S    M  
#3    M  S      G    I
#4    X  R    M    G    X
#5    Q    G      P
#6    U  W    G    B    K
#7    N    Z    X    R
#8    X  I      M    K lapply(seq_along(res),function(i) write.table(res[[i]],paste0("file",i,".txt"),row.names=FALSE,quote=FALSE))
A.K. ----- Original Message -----
From: Zilefac Elvis  
To: "r-help at r-project.org"  
Sent: Saturday, April 27, 2013 11:20 AM
Subject: [R] Help Hello, I have a question and need your help urgently. I am new to R but want to learn it. I have several files in a folder which I have imported to R using :
temp = list.files(pattern="*.txt")
>myfiles = lapply(temp, read.delim)
The resulting files are on the workspace stored as List[110]. So they are 110 files in the list. Each file has several different columns and rows.
My question: I would like to find and replace -999.99M with NA; Find 'T','C','A','F' and 'Y', delete them from all the 110 files.
Then, I want to write.table all the corrected files back to a folder on my computer.
Thanks for your help.
Atem. ________________________________
From: "r-help-request at r-project.org"   Sent: Friday, April 26, 2013 11:08 AM
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