R interview questions part 25
R interview questions part 25
Take as many assements as you can to improve your validate your skill rating
Total Questions: 20
1. dplyr can be integrated with the ________ package for large fast tables.
Correct Answer is : data.table
2. .Which of the following function is similar to summarize ?
Correct Answer is : group_by()
3. ______ let’s you perform SQL queries on your R data frames.
Correct Answer is : plyr
4. ______ splits a data frame and results an array (hence the da). Hopefully you’re getting the idea here.
Correct Answer is : daply
5. ________ makes it incredibly easy to fit time series models like ARIMA, ARMA, AR, Exponential Smoothing, etc.
Correct Answer is : forecast
6. ________ provides needed string operators in R.
Correct Answer is : stringr
7. Which of the following syntax is used to install forecast package ?
Correct Answer is : install.packages(“forecast”)
8. Which of the following convert a matrix of phi coefficients to polychoric correlations ?
Correct Answer is : phi2poly
9. Which of the following is used to plot multiple histograms ?
Correct Answer is : multi.hist
10. Which of the following count the number of good cases when doing pairwise analysis ?
Correct Answer is : count.pairwise
11. Which of the following gives the summary of values likes mean etc ?
Correct Answer is : describe
12. .The purpose of correct.cor is to correct _________ in values.
Correct Answer is : reliability
13. In practice, Line of best fit or regression line is found when _____________
Correct Answer is : Sum of the square of residuals ( ∑ (Y-h(X))2) is minimum
14. If Linear regression model perfectly first i.e., train error is zero, then _____________________
Correct Answer is : Couldn’t comment on Test error
15. Which of the following metrics can be used for evaluating regression models? i) R Squared ii) Adjusted R Squared iii) F Statistics iv) RMSE / MSE / MAE
Correct Answer is : i, ii, iii and iv
16. How many coefficients do you need to estimate in a simple linear regression model (One independent variable)?
Correct Answer is : 2
17. In a simple linear regression model (One independent variable), If we change the input variable by 1 unit. How much output variable will change?
Correct Answer is : by its slope
18. Function used for linear regression in R is __________
Correct Answer is : lm(formula, data)
19. In syntax of linear model lm(formula,data,..), data refers to ______
Correct Answer is : Vector
20. In the mathematical Equation of Linear Regression Y = β1 + β2X + ϵ, (β1, β2) refers to __________
Correct Answer is : (Y-Intercept, Slope)
