/    /  R programming – Interview questions Part 6

1. Why search() function is used?

Answer: search() function helps to see that which packages are currently loaded.


2. On which type of data binary operators are worked?

Answer: Binary operators are worked on matrices, vectors and scalars.


3. What is the use of doBY package?

Answer: It is used to define the desired table using function and model formula.


4. Which function is used to create frequency table?

Answer: Frequency table is created by table() function.


5. Define loglm() function.

Answer: Loglm() function is used to create log-linear models.


6. What is the use of corrgram() function?

Answer: corrgram() function is used to plot correlograms.


7. How to create scatterplot matrices?

Answer: Pair() or splom() function is used for create scatterplot matrices.


8. What is the use of diagnostic plots?

Answer: It is used to check the normality, heteroscedasticity and influential observations.


9. Define anova() function.

Answer: anova() is used to compare the nested models.


10. What is cv.lm() function?

Answer: It is defined under the DAAG package which is used for k-fold validation.