This document discusses various methods for exporting data from R, including write.table(), write.csv(), and writeLines(). write.table() prints data frames to file formats with options like separators, row/column names, and missing values. write.csv() is a wrapper for write.table() that outputs to CSV. writeLines() writes each row of text as one line. The document demonstrates using these functions to export an R object to files and addresses issues like extra columns.

1. Export Data
using
R Studio
Rupak Roy

2. Just like import, R also comes with rich features to export the processed data.
1. ?write.table: prints data frame into a wider range of file formats,
including tab-delimited files.
>write.table(x,file=“ ”, sep=“ ” , row.names = TRUE, col.names = TRUE, na=
“NA”, dec=“.”)
Where x = R object to be written
file = a character string naming a file
sep = “space” the field separator string. Values within each row of x will
be separated by this string.
dec = the string to use for decimal points in numeric
na = “NA” the string to use for missing values in the data
row.names = a logical value indicating whether the row names
of x are to be written along with x
col.names = a logical value indicating whether the column names
of x are to be written along with x
R Import Functions: write.table()
Rupak Roy

3. 2. ?write.csv: again it’s a wrapper function of write.table to print data
frames or a R object into csv formats.
write.csv(x, file=“ ”, row.names= F , na= “NA”)
Where x = R object to be written
na = “NA” the string to use for missing values in the data
 By default, the write.csv and write.table functions create an extra column in
the file containing the observation numbers. To prevent this, set
the row.names argument to F.
 > write.csv(x, "filename.csv, row.names=F)
R Import Functions: write.csv()
Rupak Roy

4. 3. ?writeLines: writes text line to a file i.e. prints the entire row as one line
>writeLines(X, file=“ ”, sep = “,")
Where x = R object to be written, example: product$reviews_column
file = “filename” character string value to used to save the file
sep = “,” character string to be written to the connection after each
line of text.
R Import Functions: writeLines()
Rupak Roy

5. write.table()
>write.table(bike_sharing_program,file = "bikesharingprogramtable.csv",sep =
",",col.names = T,na="NA")
We will observe that it creates an extra
column in the file containing the
observation numbers for the
R object (bike_sharing_program) in the
bikesharingprogramtable.csv file
causing the column values shift to the right,
like fueltype should be ‘gas’ instead of ‘1’
To overcome this issue we need to declare
one more function row.names = F or FALSE
indicating row names already exists
with the R object bike_sharing_program

6. write.table()
>write.table(bike_sharing_program,file = "bikesharingprogramtable.csv",sep =
",",col.names = T, row.names = F, na="NA")
Now, by default it didn’t create an extra
column in the file containing the
observation numbers for the
R object bike_sharing_program in the
bikesharingprogramtable.csv
Hence proper alignment of all the
variable values

7. write.csv()
>write.csv(bike_sharing_program,file = "bikesharingprogramtable1.csv",
row.names = F, na="NA")
However in write.csv parameters like
col.names, sep= “ ,” will throw an error
as write.csv already contains delimiter.

8. writeLines()
>str(bike_sharing_program)
To perform writeLines() we need character variables/data type. So we will
convert one of the variables for example ‘aspiration’ into character data type
>bike_sharing_program$aspiration<-
as.character(bike_sharing_program$aspiration)
>str(bike_sharing_program$aspiration)
>writeLines(bike_sharing_program$aspiration,"bike.txt", sep = "n")
We can perform the same using an another function call CAT()
>cat(bike_sharing_program$aspiration, sep = ",", file = "bike1.txt")

9. Next:
We will see how to perform import and export in the lab
session.
Import & Export Data
Rupak Roy