[R] subset data.frame with value != in all columns

[Chuck Cleland]

How about this?

#extract data.frame of rows with -99 in them

subset(x, apply(x, 1, function(x){any(x == -99)}))

#extract data.frame of rows not containing -99 in them

subset(x, apply(x, 1, function(x){all(x != -99)}))

hope this helps,

Chuck Cleland

Tim Howard wrote:
> I am trying to extract rows from a data.frame based on the
> presence/absence of a single value in any column.  I've figured out how
> to do get the positive matches, but the remainder (rows without this
> value) eludes me.  Mining the help pages and archives brought me,
> frustratingly,  very close, as you'll see below. 
> 
> My goal: two data frames, one with -99 in at least one column in each
> row, one with no occurrences of -99. I want to preserve rownames in
> each.
> 
> My questions: 
> Is there a cleaner way to extract all rows containing a specified
> value?
> How can I extract all rows that don't have this value in any col?
> 
> #create dummy dataset
> x <- data.frame(
> c1=c(-99,-99,-99,4:10),
> c2=1:10,
> c3=c(1:3,-99,5:10),
> c4=c(10:1),
> c5=c(1:9,-99))
> 
> #extract data.frame of rows with -99 in them
> for(i in 1:ncol(x))
> {
> y<-subset(x, x[,i]==-99, drop=FALSE);
> ifelse(i==1, z<-y, z <- rbind(z,y));
> }
> 
> #various attempts to get rows not containing "-99":
> 
> # this attempt was to create, in "list", the exclusion formula for each
> column.
> # Here, I couldn't get subset to recognize "list" as the correct type.
> # e.g. it works if I paste the value of list in the subset command
> {
> for(i in 1:ncol(x)){
> if(i==1)
> list<-paste("x[",i,"]!=-99", sep="")
> else
> list<-paste(list," ", " & x[",i,"]!=-99", sep="")
> }
> y<-subset(x, list, drop=FALSE);
> }
> 
> # this will do it for one col, but if I index more
> # it returns all rows
> y <- x[!(x[,3] %in% -99),]
> 
> # this also works for one col
> y<-x[x[,1]!=-99,]
> 
> # but if I index more, I get extra rows of NAs
> y<-x[x[,1:5]!=-99,]
> 
> Thanks in advance.
> Tim Howard
> 
> platform i386-pc-mingw32
> arch     i386           
> os       mingw32        
> system   i386, mingw32  
> status                  
> major    2              
> minor    0.1            
> year     2004           
> month    11             
> day      15             
> language R
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
> 

-- 
Chuck Cleland, Ph.D.
NDRI, Inc.
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