Homework 1

R Basics

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Problem 1:

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

.Subtraction .Multiplication .square root

15-1.5

## [1] 13.5

15*1.5

## [1] 22.5

sqrt(15)

## [1] 3.872983

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
avg<- mean(scores)
avg<-round(avg, digits=2)
print(avg)

## [1] 73.28

#Find the Maximum and Minimum score
highest_score <- max(scores) #maximum score
lowest_score <- min(scores) #minimum score 
highest_score

## [1] 100

lowest_score

## [1] 0

#Find how many scores were above the average, use coding for this
 scores[scores>avg]

## [1]  87.0 100.0  91.0  95.0  81.5  74.0  92.0

#Create a new set called new_scores that includes the elements from indices 2 to 6 of the scores vector
 new_scores <- c(scores[2:6])
 new_scores

## [1] 100.0  91.0  95.0  81.5   0.0

Problem 3:

Read section 2.3, then answer the following questions

# Create a vector with the number 1 repeated 5 times. Print it
  rep_x <- rep(1, times=5)
  rep_x

## [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
vec_x <- c(1:10)
print(vec_x)

##  [1]  1  2  3  4  5  6  7  8  9 10

# Create a vector by repeating a sequence from 1 to 3, 2 times. Print it.
  vec_2<- rep(1:3, times=2)
  vec_2

## [1] 1 2 3 1 2 3

Problem 4

mixed_vector <- c(1, "two", 3.0, TRUE, 2)

# Check the class of the vector
 class(mixed_vector)

## [1] "character"

## Coerce to numeric and print it 
as.numeric(mixed_vector)

## Warning: NAs introduced by coercion

## [1]  1 NA  3 NA  2

print(mixed_vector)