Data Science Interview questions on R – Part 1


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Here is the first list of Interview questions on R (more to come in next posts, please subscribe and get notified as and when the posts are here):

1.      What are the different data objects in R?
2.      What is R Base package?
3.      What are the different data objects in R?
4.      What are the different data structures R contain?
5.      How to combine data frames?
6.      How to check correlation with R?
7.      How to fine tune random forest model?
8.      How to combine data by rows when different number of columns?
9.      Which data structure is used to store categorical variables?
10.     How can you merge two data frames in R language?
11.     How to calculate cartesian product of two datasets?
12.     How to extract last name from full name?
13.     How to extract first 3 characters from a word?
14.     How to check the frequency distribution of a categorical variable?
15.     How to check the cumulative frequency distribution of a categorical variable
16.     What is the difference between data frame and a matrix in R?
17.     Multiplication of 2 vectors having different length
18.     Differentiate between lapply and sapply.
19.     What is the use of with() and by() functions? What are its alternatives?
20.     What is the difference between R-square and adjusted R-square?
21.     How will you measure the probability of a binary response variable in R language?
22.     How can you verify if a given object “X” is a matrix data object?
23.     Difference between sort() and order() functions
24.     Popular R packages for decision tree
25.     How to transpose data in R?
26.     How to remove duplicates in R?
27.     Popular packages to handle big data?
28.     How to perform LEFT join in R?
29.     What are various ways to write loop in R
30.     How R handles missing values?
31.     How to concatenate two strings?
32.     How to calculate max value for rows?
33.     How to convert a factor variable to numeric?
34.     How to read large CSV file in R?
35.     How to standardize variables?
36.     How to rename a variable?
37.     How to calculate first non-missing value in variables?
38.     How to join vertically two data frames
39.     Use of with() and by() functions
40.     Use of which() function
41.     Which package is generally used for fast data manipulation on large datasets?
42.     Which package is used for market basket analysis?
43.     How to measure execution time of a program in R?