/    /  R programming – Interview questions Part 8

1. What is fligner.test()?

Answer: It is a function which provides a non-parametric k sample test of the equality of variances.

 

2. Define hovplot().

Answer: It is define in HH package which provides a graphic test of homogeneity of variance based on brown forsyth.

 

3. Which variables are represented by lower case letters?

Answer: Numerical variables are represented by lower case letters.

 

4. Which variables are represented by upper case letters?

Answer: Categorical factors are represented by upper case letters.

 

5. What is logistic regression?

Answer: Logistic regression is used to predict the binary outcome from the given set of continuous predictor variables.

 

6. Define Poison regression.

Answer: It is used to predict the outcome variable which represents counts from the given set of continuous predictor variable.

 

7. Define Survival analysis.

Answer: It includes number of techniques which is used for modeling the time to an event.

 

8. What is the use survfit() function?

Answer: It estimates a survival distribution one or more groups.

 

9. Define survdiff().

Answer: It determines the differences in survival distribution between two or more groups.

 

10. What is coxph()?

Answer: It is a function which is used to model the hazard function on the set of predictor variable.