CODEWITHSUNDEEP
rcsvread.table
Jon Claus
Jon Claus

Reputation: 2932

Reading a CSV file organized horizontally

In R, is there a function like read.csv that reads in files where the headers are on the left (or right) as opposed to the top and the data is organized from left to right?

So the data would look like:

var1,1,2,3,4,5

Looking at the documentation for read.table and read.csv, nothing seems to pop out. The best option I see using those functions is to use read.table and then construct another table whose columns are the rows of the original data and so forth.

Upvotes: 15

Views: 12792

Answers (1)

Ricardo Oliveros-Ramos
Ricardo Oliveros-Ramos

Reputation: 4339

Let's say your file is called 'data.csv' and it contains:

var1,1,2,3,4,5,6
var2,2.1,3.9,4.6,5.2,6.1
var3,M,F,M,F,M,M

Note var1 and var3 have 6 values but var2 has only 5. So, the idea is to read the data, transpose it and then use read.csv.

read.tcsv = function(file, header=TRUE, sep=",", ...) {

  n = max(count.fields(file, sep=sep), na.rm=TRUE)
  x = readLines(file)

  .splitvar = function(x, sep, n) {
    var = unlist(strsplit(x, split=sep))
    length(var) = n
    return(var)
  }

  x = do.call(cbind, lapply(x, .splitvar, sep=sep, n=n))
  x = apply(x, 1, paste, collapse=sep) 
  out = read.csv(text=x, sep=sep, header=header, ...)
  return(out)

}

Then, you can do:

read.tcsv("data.csv")

  var1 var2 var3
1    1  2.1    M
2    2  3.9    F
3    3  4.6    M
4    4  5.2    F
5    5  6.1    M
6    6   NA    M

Upvotes: 26

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