How To Import Data from a File in R Programming

Import Data from a File in detail

Data is a collection of facts and can exist in multiple formats. To analyze data using the R programming language, it first needs to be imported. R allows importing data from various file types such as text files, CSV, and other delimiter-separated files. Once imported, users can manipulate, analyze, and generate reports from the data.

Importing Data from Files into R

This guide demonstrates how to import different file formats into R programming.

Importing CSV Files

Method 1: Using read.csv()

The read.csv() function is a straightforward method for importing CSV files.

read.csv(file_path, header = TRUE, sep = ",")

Arguments:

• file_path: The file’s location.
• header: TRUE (default) to indicate column headings.
• sep: The separator for values in each row (default is a comma ,).

Example:

# Specify file path
file_path <- "data.csv"

# Read the CSV file
content <- read.csv(file_path)

# Print file contents
print(content)

Output:

ID Name   Role Age
1  1  Alex  Dev  30
2  2  Sam   QA   25
3  3  Emma  HR   28

Method 2: Using read.table()

Another way to import CSV files is by using read.table().

# Import CSV using read.table()
data <- read.table("C://data//records.csv", header = TRUE, sep = ",")

# Print file contents
print(data)

Output:

Col1 Col2 Col3
1  101  A1   B1
2  202  A2   B2
3  303  A3   B3

Importing Data from a Text File

read.table() can also be used for importing text files.

Syntax:

read.table("file.txt", header = TRUE/FALSE)

Example:

# Read text file
data <- read.table("C://data//records.txt", header = FALSE)

# Print file contents
print(data)

Output:

V1  V2  V3
1 200  A1  B1
2 300  A2  B2
3 400  A3  B3

Importing Data from a Delimited File

The read.delim() function is used to import delimited files, where values are separated by specific symbols such as |, $, or ,.

Syntax:

read.delim("file.txt", sep="|", header=TRUE)

Example:

# Read a delimited file
data <- read.delim("C://data//info.txt", sep="|", header=TRUE)

# Print file contents
print(data)

Output:

$ID
[1] "101" "102" "103"
$Name
[1] "John" "Lily" "Raj"
$Salary
[1] "1500" "2000" "2500"

Importing XML Files

To import XML files, use the XML package.

XML File Sample:

<RECORDS>
  <EMPLOYEE>
    <ID>1</ID>
    <NAME>Adam</NAME>
    <SALARY>5000</SALARY>
  </EMPLOYEE>
  <EMPLOYEE>
    <ID>2</ID>
    <NAME>Sophia</NAME>
    <SALARY>6000</SALARY>
  </EMPLOYEE>
</RECORDS>

Example:

# Load XML package
library("XML")

# Parse XML file
data <- xmlParse(file = "C://data//employees.xml")

# Print parsed data
print(data)

Output:

1  Adam   5000
2  Sophia 6000

Importing SPSS Files

SPSS .sav files can be imported using the haven package.

Syntax:

read_sav("file.sav")

Example:

# Load haven package
library("haven")

# Read SPSS file
data <- read_sav("C://data//survey.sav")

# Print data
print(data)

Output:

ID   Age  Response  Score
1  1   23   Agree     4.5
2  2   30   Neutral   3.0
3  3   27   Disagree  2.5