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

#subtraction
54-23

## [1] 31

#Multiplication
1.5 * 15

## [1] 22.5

#Square Root
sqrt(23)

## [1] 4.795832

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
round(mean(scores),2)

## [1] 73.28

#Find the Maximum and Minimum score

#Maximum
max(scores)

## [1] 100

#Minimum
min(scores)

## [1] 0

#Find how many scores were above the average, use coding for this
sum(scores > (mean(scores)))

## [1] 7

#Create a new set called new_scores that includes the elements from indices 2 to 6 of the scores vector

# *NOTE* trunc() truncates to remove the decimals since initially the vector would print 100.0, 91.0, 95.0, ...etc
new_scores <- trunc(scores[2:6])
new_scores

## [1] 100  91  95  81   0

Problem 3:

Read section 2.3, then answer the following questions

# Create a vector with the number 1 repeated 5 times. Print it
vec_1 <- rep(1,5)
vec_1

## [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_2 <- seq(1,10, by= 2)
vec_2

## [1] 1 3 5 7 9

# Create a vector by repeating a sequence from 1 to 3, 2 times. Print it.
vec_3 <- rep(seq(1,3),2)
vec_3

## [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 

# *NOTE* suppressWarnings get rid of the warning for the NAs
num_vec <-suppressWarnings(as.numeric(mixed_vector))
num_vec