/    /  R programming – Interview questions Part 5

1. How to create axes in the graph?

Answer: Using axes() function custom axes are created.


2. What is the use of abline() function?

Answer: abline() function is add the reference line to a graph.


abline(h=yvalues, v=xvalues)


3. Why vcd package is used?

Answer: vcd package provides different methods for visualizing multivariate categorical data.


4. What is GGobi?

Answer: It is an open source program for visualization for exploring high dimensional typed data.


5. What is iPlots?

Answer: It is a package which provide bar plots, mosaic plots, box plots, parallel plots, scatter plots and histograms.


6. What is the use of lattice package?

Answer: lattice package is to improve on base R graphics by giving better defaults and it have the ability to easily display multivariate relationships.


7. What is fitdistr() function?

Answer: It is used to provide the maximum likelihood fitting of univariate distributions. It is defined under the MASS package.


8. Which data structures are used to perform statistical analysis and create graphs.

Answer: Data structures are vectors, arrays, data frames and matrices.


9. What is the use of sink() function?

Answer: It defines the direction of output.


10. Why library() function is used?

Answer: This function is used to show the packages which are installed.