R Basics

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Problem 1:

  1. From set = {1.5, 15, 0, 54, 23}, pick two numbers and perform the Following Operations:

.Subtraction .Multiplication .square root

# subtraction 
 54-23
## [1] 31
#multiplication 
1.5*15
## [1] 22.5
# Square root 
sqrt(54)
## [1] 7.348469

Problem 2

Suppose you have a set of numbers representing the assignments scores:

scores <- c(87,100, 91, 95, 81.5, 0, 39, 74, 92)

#Calculate the average of the scores, and round your answer to two decimal number

 average_score <- sum(scores)/9
round(average_score, 2)
## [1] 73.28
#Find the Maximum and Minimum score
max(scores) 
## [1] 100
min(scores)
## [1] 0
#Find how many scores were above the average, use coding for this
 avg <- mean(scores)

above_averagenum <- sum(scores > avg)
  
  
 print(above_averagenum)
## [1] 7
#create a new set of scores, call it new_scores.  The new list should include elements 2 to 6
new_scores <- scores[2:6]
print(new_scores)
## [1] 100.0  91.0  95.0  81.5   0.0

Problem 3: Read section 2.3

# Create a vector with the number 1 repeated 5 times. Print it

numberone <- c(1,1,1,1,1)
print(numberone)
## [1] 1 1 1 1 1
# Create a vector with a sequence of numbers from 1 to 10 with a step of 2. Print it

sequence_oneto10 <- seq(1, 10, by = 2)
print(sequence_oneto10)
## [1] 1 3 5 7 9
# Create a vector by repeating a sequence from 1 to 3, 2 times. call it

rep <- rep(1:3 , time =  2)

Problem 4

# Create a vector with different class types
mixed_vector <- list(1, "two", 3.0, TRUE, 2)

# Check the class of the vector
check_classes <- lapply(mixed_vector, class)
print(check_classes)
## [[1]]
## [1] "numeric"
## 
## [[2]]
## [1] "character"
## 
## [[3]]
## [1] "numeric"
## 
## [[4]]
## [1] "logical"
## 
## [[5]]
## [1] "numeric"
## Coerce to numeric and print it 
setnumeric <- sapply(mixed_vector, as.numeric)
## Warning in lapply(X = X, FUN = FUN, ...): NAs introduced by coercion
print(setnumeric)
## [1]  1 NA  3  1  2