Getting Started with R | R Language Practical Slip With Solution - letsbug

    In this article we are solving some R programming questions that might get asked in an exam. These examples are simple and after solving these one will have a better understanding of R language. But before we start make sure you have a IDE or a text editor where you can run your R program. You should also have R language installed on your system for it to work.

    Now let's start fire up you code editor. I am using VS code for R, not necessary you can have R Studio.  Now let's start 

    R language practicals

1. R program to find the maximum and the minimum value of a given vector.

code:

x = c(10,20,30,25,9, 36)
print("Original Value")
print(x)
print("Maximum value of the above Vector")
print(max(x))
print("Minimum value of the above Vector")
print(min(x))

output:

[1] "Original Value"
[1] 10 20 30 25  9 36
[1] "Maximum value of the above Vector"
[1] 36
[1] "Minimum value of the above Vector"
[1] 9

2. R program to sort a vector in ascending and descending order

code:

x = c(10,20,03,030, 24,9,35)
print("Original Value:")
print(x)
print("Sorting in ascending order:")
print(sort(x))
print("Sorting in descending order:")
print(sort(x, decreasing=TRUE))

output:

[1] "Original Value:"

[1] 10 20  3 30 24  9 35

[1] "Sorting in ascending order:"

[1]  3  9 10 20 24 30 35

[1] "Sorting in descending order:"

[1] 35 30 24 20 10  9  3

3. R program to compare two data frames to find the elements in first dataframe that are not present in second dataframe.

code:

a = c("a", "b", "c", "d", "e")
b = c("d", "e", "f", "g")
print("Original Dataframes")
print(a)
print(b)
print("Data in first dataframe that are not present in second dataframe:")
result = setdiff(a, b)
print(result)

output:

[1] "Original Dataframes"

[1] "a" "b" "c" "d" "e"

[1] "d" "e" "f" "g"

[1] "Data in first dataframe that are not present in second dataframe:"

[1] "a" "b" "c"

4. R program to extract first 10 english letter in lowercase  and last 10 letters in upper case and extract letters between 22nd and 24th letters in upper case.

code:

print("First 10 letters in lowercase")
t = head(letters, 10)
print(t)
print("Last 10 letters in Uppercase")
t = tail(LETTERS, 10)
print(t)
print("Letters between 22nd to 24th in uppercase")
e = tail(LETTERS[22:24])
print(e)

output:

[1] "First 10 letters in lowercase"

 [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"

[1] "Last 10 letters in Uppercase"

 [1] "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z"

[1] "Letters between 22nd to 24th in uppercase"

[1] "V" "W" "X"

5. R program to create a simple bar plot of five subject's marks.

code:

marks = c(70, 95, 80, 74)
barplot(marks,
main = "Comparing Marks Of 5 Subjects",
xlab = "Subject",
ylab = "Marks",
names.arg = c("English", "Science", "Math", "History"),
col = "blue",
horiz = FALSE
)

output:

output

6. R program to find sum, mean and product of a vector.

code:

x = c(10,20,30)
print("Sum:")
print(sum(x))
print("Mean:")
print(mean(x))
print("Product:")
print(prod(x))

output:

[1] "Sum:"

[1] 60

[1] "Mean:"

[1] 20

[1] "Product:"

[1] 6000

7. R program to create a data frames which contain details of 5 employees and display the details in ascending order.

code:

Employees = data.frame(
    Name=c("Aniket", "Swastik", "Suyash", "Pranav", "Ibrahim"),
    Gender=c("M", "M", "M", "M", "M"),
    Age=c(23,22,25,26, 32),
    Designation=c("CEO", "Manager", "Exective", "HR", "Assistant"),
    SSN=c("123-34-2346", "123-44-779", "556-24-433", "123-09-987", "679-77-576")
)
print("Details of the employees: ")
print(Employees)

output:

[1] "Details of the employees: "

     Name Gender Age Designation         SSN

1  Aniket      M  23         CEO 123-34-2346

2 Swastik      M  22     Manager  123-44-779

3  Suyash      M  25    Exective  556-24-433

4  Pranav      M  26          HR  123-09-987

5 Ibrahim      M  32   Assistant  679-77-576

8. R program to create a data frame using two given vectors and display the duplicated elements and unique rows of the said data frame.

code:

a = c(10,20,10,10,40,50,20,30)
b = c(10,30,10,20,0,50,30,30)
print("Original Dataframe: ")
ab = data.frame(a,b)
print(ab)
print("Duplicate elements of the said data frame:")
print(duplicated(ab))
print("Unique row of the said dataframe:")
print(unique(ab))

output:

[1] "Original Dataframe: "

   a  b

1 10 10

2 20 30

3 10 10

4 10 20

5 40  0

6 50 50

7 20 30

8 30 30

[1] "Duplicate elements of the said data frame:"

[1] FALSE FALSE  TRUE FALSE FALSE FALSE  TRUE FALSE

[1] "Unique row of the said dataframe:"

   a  b

1 10 10

2 20 30

4 10 20

5 40  0

6 50 50

8 30 30

9. R program to change the first level of a factor with another level of a given factor.

code:

v = c("a", "b", "a", "c", "b")
print("Original vector:")
print(v)
f = factor(v)
print("Factor of the said vector: ")
print(f)
levels(f)[1] = "e"
print(f)

output:

[1] "Original vector:"

[1] "a" "b" "a" "c" "b"

[1] "Factor of the said vector: "

[1] a b a c b

Levels: a b c

[1] e b e c b

Levels: e b c

10. R program to create two vectors of different lengths and give these vectors as input to array and print addition and subtraction of those matrices.

code:

print("Two vectors of different lengths: ")
v1 = c(1,3,4,5)
v2 = c(10,11,13,12,14,15)
print(v1)
print(v2)
result = array(
    c(v1, v2),
    dim = c(3,3,2)   
)
print("New Array: ")
print(result)
print("The second row of the second matrix of the array: ")
print(result[2,,2])
print("The element in the 3rd row and 3rd column of the 1st matrix: ")
print(result[3,3,1])

output:

[1] "Two vectors of different lengths: "

[1] 1 3 4 5

[1] 10 11 13 12 14 15

[1] "New Array: "

, , 1

     [,1] [,2] [,3]

[1,]    1    5   13

[2,]    3   10   12

[3,]    4   11   14

, , 2

     [,1] [,2] [,3]

[1,]   15    4   11

[2,]    1    5   13

[3,]    3   10   12

[1] "The second row of the second matrix of the array: "

[1]  1  5 13

[1] "The element in the 3rd row and 3rd column of the 1st matrix: "

[1] 14

Thankyou.