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R is a well-known programming language used for data visualization, forecast analysis, statistical analysis, predictive modeling, and many more. There are a lot of opportunities from various reputed companies all over the world. This blog covers all the important R interview questions and answers that would help you prepare and crack the interview.

Top R Interview Questions & Answers

1. What is R

R is the open-source programming language created by Robert Gentleman and Ross Ihaka in Auckland, New Zealand. Data Scientists mainly used it to analyze statistical information, reporting, modeling, and graphical representation. It includes machine learning algorithms, time series, statistical inference, and linear regression. 

2. Explain how to import data in R? 

The following are three ways to import data in R:

• Import Data from plain text (ASCII) or other files such as Minitab, SPSS, etc.
• Read a data set or select the data set in the dialog box or type the name of the data set 
• Enter the data directly through Data> New Data Set

3. Explain how R commands are written?

The line of code in R begins with # sign such as:

• #division
• #subtraction
• #note code of operations exists

4. Name some of the functions that R provides

• Mean
• Median
• Covariance
• Distribution
• Non-linear
• Mixed Effects
• GAM
• GLM, etc.

5. What are the packages used for data mining in R? 

The following are the packages used for data mining in R:

• data.table: provides a fast reading of large files
• Forecast: provides functions for time series analysis.
• rpart and caret: for machine learning models.
• Arules: an infrastructure for representing, manipulating, analyzing data patterns and transactions.
• GGplot: provides various data visualization plots.
• tm: to perform text mining.

6. What are the various graphical representations used in R?

The R programming language contains various libraries to create graphical representations. The following are the types of available graphical representations used in R:

1. Pie charts
2. Bar charts
3. Box Plots
4. Histograms
5. Line graphs
6. Scatterplots

7. Explain how you would save the data in R?

There are various ways to save the data in R, but the most commonly used method is: 
Go to Data > Active Data Set > Export Active Data Set, and a dialogue box will appear. When you click ok, the dialogue box lets you save your data in the usual way.

8. What are data structures used to perform statistical analysis and create graphs in R?

The following data structures were used to perform statistical analysis and create graphs in R:

• Matrices
• Arrays
• Data frames
• Vectors

9. What are the features of R 

R is a data analysis software

1. It provides adequate storage facility and data handling
2. It is a simple, effective, and interpreted programming language
3. It offers a high extensible graphical methods

10. List out topmost companies that use R

• Google
• Wipro
• Bing
• Genpact
• Facebook
• Accenture, etc.

Final words

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