[R] Convert char vector to numeric table

[Spencer Graves]

Have you considered something like the following:

 > tst <- c("     23.4   1.5   4.2", "     19.1   2.2   4.1")
 > num1 <- regexpr("[0-9]", tst)
 > tst1 <- substring(tst, num1)
 > b1 <- regexpr(" ", tst1)
 > x1 <- as.numeric(substring(tst1, 1, num1))
 > tst <- substring(tst1, b1)
 > x1; tst
[1] 23.4 19.1
[1] "   1.5   4.2" "   2.2   4.1"

You can put this in a loop with appropriate modification for the end of 
the strings, etc.

Will this solve your problems?
Best Wishes,
Spencer Graves

Nurnberg-LaZerte wrote:
> I'm a great fan of read.table(), but this time the data had a lot of cruft. So I used readLines() and editted the char vector to eventually get something like this:
> "     23.4   1.5   4.2"
> "     19.1   2.2   4.1"
> and so on. To get that into a 3 col numeric table, I first just used:
> 
> writeLines(data,"tempfile")
> read.table("tempfile",col.names=c("A","B","C"))
> 
> Works fine, but writing to a temporary file seems ... inelegant?  And read.table() doesn't take a char vector as a file or connection argument. The following works but it seems like a lot of code: 
> 
> data <- sub(" +","",data)   		# remove leading blanks for strsplit
> data <- strsplit(data," +")   		# strsplit returns a list of char vectors
> ndata <- character(0)			# vectorize the list of char vectors
> for (ii in 1:length(data)) ndata <- c(ndata,data[[ii]])  
> ndata <- as.numeric(ndata)				
> dim(ndata) <- c(3,length(data))	  	
> data <- t(ndata)
> data.frame(A=data[,1],B=data[,2],C=data[,3])
> 
> Am I missing something?
> 
> Thanks,
> Bruce L.
> 
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