colClasses=
is working but the problem is that on your system default action when import data is to convert character columns to factor.
If you import test.xlsx
and set that all columns should be "character"
, you see that all columns are made as factors (also numbers).
d2 = read.xlsx('test.xlsx', sheetName='Sheet1', colClasses=rep("character",4))
str(d2)
'data.frame': 3 obs. of 4 variables:
$ A: Factor w/ 3 levels "A","B","C": 1 2 3
$ B: Factor w/ 3 levels "a","b","c": 1 2 3
$ C: Factor w/ 3 levels "1","2","3": 1 2 3
$ D: Factor w/ 1 level "1.1": 1 NA NA
To ensure that characters are not converted to factors you can add argument stringsAsFactors=FALSE
to function read.xlsx()
.
d2 = read.xlsx('test.xlsx', sheetName='Sheet1',
colClasses=c(B='character', A='character'),stringsAsFactors=FALSE)
str(d2)
'data.frame': 3 obs. of 4 variables:
$ A: chr "A" "B" "C"
$ B: chr "a" "b" "c"
$ C: num 1 2 3
$ D: num 1.1 NA NA