Issue with read.csv treatment of numerics enclosed in quotes (and a confession)
Hi Chris, Yes, you're missing something: the colClasses argument to read.csv. Given a tiny little csv file that looks like this: 1,2,3,"01234" 4,5,6,"00011" 7,8,0,"00000"
testdata <- read.csv("testdata.csv", header=FALSE, colClasses=c(NA, NA, NA, "character"))
testdata
V1 V2 V3 V4 1 1 2 3 01234 2 4 5 6 00011 3 7 8 0 00000
str(testdata)
'data.frame': 3 obs. of 4 variables: $ V1: int 1 4 7 $ V2: int 2 5 8 $ V3: int 3 6 0 $ V4: chr "01234" "00011" "00000" That should do what you want. Not that you should need it, but sprintf() is a neater way to pad out numeric to character values:
sprintf("%05d", 12)
[1] "00012"
sprintf("%05d", 1223)
[1] "01223"
sprintf("%07d", 12)
[1] "0000012"
Hope that solves your problem, Sarah
On Wed, Oct 5, 2011 at 8:24 PM, Chris Conner <connerpharmd at yahoo.com> wrote:
Dear Help-Rs,
I've been dealing with this problem for some?time, using a work-around to deal with it. It's time for me to come clean with my ineptitude and seek a what has got to be a more streamlined solution from the Help-Rverse.
I regularly import delimited text data that contains numerics enclosed in quotes (e.g., "00765288071").? Thing is, for some of these data, I need to keep the values as "character" class within the data frame (that is to say the leading zeros are important and I would like them to stay).? Here is an example of the code I would use to read an example dataset in question:
mydata <- read.csv("~/mydata.csv", quote = "\"'")
The problem is, when R reads the data and converts them into a data frame, inevitably, R ignores the quotes around values like the above, and reads them in as "numeric".? So R strips the valuable leading zeros and converts my "00765288071" to 765288071.? I've developed a work-arounds to this involving the use of the following:
whatIneed <- "00000000000" whatIgot <- 765288071 whatIgot <- as.character(whatIgot) substr(whatIneed, 1+nchar(whatIneed)-nchar(whatIgot), nchar(whatIneed)) <- whatIgot whatIneed
[1] "00765288071" My question is, am I missing something in how I'm writing my read.csv statement that would indicate to R that numerics enclosed in quotes should be read and imported as characters and not converted to numerics???
Sarah Goslee http://www.functionaldiversity.org