Project Instructions

In this project you will produce and submit two files. The first is an R script that you create by following the instructions below. The second is a report containing answers and visualizations as specified in the following instructions. Be sure to follow all formatting guidelines.

Setting Up Your Project

When working in RStudio, be careful with cloud drives. RStudio does not always play well with cloud drives’ longer file path names. You will be best served by using a local drive

whenever possible until you are comfortable troubleshooting technical issues.

1.     Create a new project titled “Lastname-Project1”.  For example, if your lastname is Smith your project would be titled “Smith-Project1” .

2.     Create an R Script file within your project titled “Lastname-Project1.R”. As before, if you lastname is Smith, you file should be titled “Smith-Project1.R”.

3.      Include your name, the date, and class in a comment as the first line of the script.

4.      Include the following code at the very top of every R file you create. This will clear out the environment each time you run your entire code and prevent past actions  from interfering with current work.

cat("\014")  # clears console

rm(list = ls())  # clears global environment

try(dev.off(dev.list()["RStudioGD"]), silent = TRUE) # clears plots try(p_unload(p_loaded(), character.only = TRUE), silent = TRUE) #

clears packages

options(scipen = 100) # disables scientific notation for entire R session

5.      [Optional] Install the pacman package. This is a simple, user-friendly package that makes installing and loading other packages a one-line process.

# You should do this line only once in the entire course. install.packages("pacman")

# Once you have done the install line, the following line is what you

will always need to do to utilize the pacman package in R

library(pacman)

Testing Your Solution

The file project1_tests.R contains a set of testcases which will affirm that some of the problems you have solved are correct. To use this file, save it into your project folder.

Then, from the console line write the following code:

library(pacman)

p_load(testthat)

test_file("project1_tests.R")

Tests can be run at anytime. This code will report the total number of tested items that currently succeed as well as any errors preventing you from passing others. A single

problem may have multiple tests while others have none. You should be able to complete

this project with 100% accuracy on all tests. Use the exact names of variables stated in each problem, pay extra attention to matching any upper and lowercase letters.

Project 1 Instructions

Complete the following problems in the R script you created above. Be sure to name

specified variables exactly as they are given, paying special attention to spellings and the use of upper and lowercase letters.

1.     Write lines of code to compute all of the following. Include the answers in your written report.

123 * 453

5^2 * 40

TRUE & FALSE

TRUE | FALSE

75 %% 10

75 / 10

2.      Create a vector using the c function with the values 17, 12, -33, 5 and assign it to a variable called first_vector.

[1]  17  12 -33   5

3.      Create a vector using the c function with the values 5, 10, 15, 20, 25, 30, 35 and assign it to a variable called counting_by_fives.

13.   Create a vector with values from 100 to - 100 by 3s. Store the result in a variable

called reverse_numbers. To clarify, the first 3 numbers in this vector will be (100, 97, 94…)

[1] 100  97  94  91  88  85  82  79  76  73  70  67  64  61  58  55

52  49  46

[20]  43  40  37  34  31  28  25  22  19  16  13  10   7   4   1  -2  - 5  -8 -11

[39] -14 -17 -20 -23 -26 -29 -32 -35 -38 -41 -44 -47 -50 -53 -56 -59 - 62 -65 -68

[58] -71 -74 -77 -80 -83 -86 -89 -92 -95 -98

14.   Write each of the following lines of code. Add a one-sentence comment above each line explaining what is happening. Include your comments in the written report.

second_vector + 20

second_vector * 20

second_vector >= 20

second_vector != 20  # != means "not equal"

15.   Using the built in sum function, compute the sum of one_to_one_hundred and store it in avariable called total.

[1] 5050

16.   Using the built in mean function, compute the average of one_to_one_hundred and store the result in a variable called average_value.

[1] 50.5

17.   Using the built in median function, compute the average of one_to_one_hundred and store the result in a variable called median_value.

[1] 50.5

18.   Using the built in max function, compute the average of one_to_one_hundred and store the result in a variable called max_value.

[1] 100

19.   Using the built in min function, compute the average of one_to_one_hundred and store the result in a variable called min_value.

[1] 1

20.   Using brackets, extract the first value from second_vector and store it in a variable called first_value.

[1] 10

21.   Using brackets,extract the first, second and third values from second_vector and store it in avariable called first_three_values.

[1] 10 12 14

22.   Using brackets, extract the 1st, 5th, 10th, and 11th elements of second_vector. Store the resulting vector in a variable called vector_from_brackets.

[1] 10 18 28 30

23.   Use the brackets to extract elements from the first_vector using the following vector c(FALSE, TRUE, FALSE, TRUE). Store the result in a variable called

vector_from_boolean_brackets. Explain in a comment what happens. Include the answer in your written report.

[1] 12  5

24.   Examine the following piece of code and write a one-sentence comment explaining what is happening. Include the answer in your written report.

second_vector >= 20

25.   Examine the following piece of code and write a one-sentence comment explaining what is happening.

ages_vector <- seq(from = 10, to = 30, by = 2)

26.   Examine the following piece of code and write a one-sentence comment explaining what is happening, assuming ages_vector was computed in the previous problem.  Include the answers in your written report.

ages_vector [ages_vector >= 20]

27.   Using the same approach as the previous question, create a new vector by removing from the grades vector all values lower than or equal to 85. Store the new vector in  a variable called lowest_grades_removed.

[1]  96 100  85  92

28.   Use the grades vector to create a new vector with the 3rd and 4th elements of grades removed. Store this in a variable called middle_grades_removed. Try utilizing a vector of negative indexes to complete this task.

[1]  96 100  81  72

29.   Use bracket notation to remove the 5th and 10th elements of second_vector. Store the result in a variable called fifth_vector.

[1] 10 12 14 16 20 22 24 26 30

30.   Write the following code. Explain in a comment what you think the code is doing. Include the answer in your written report.

set.seed(5)

random_vector <- runif(n=10, min = 0, max = 1000)

31.   Use the sum function to compute the total of random_vector. Store the result in a variable called sum_vector.

[1] 5295.264

32.   Use the cumsum function to compute the cumulative sum of random_vector. Store the result in a variable called cumsum_vector.

[1]  200.2145  885.4330 1802.3088 2086.7083 2191.3584 2892.4159 3420.3759

[8] 4228.3111 5184.8112 5295.2642

33.   Use the mean function to compute the mean of random_vector. Store the result in a variable called mean_vector.

[1] 529.5264

34.   Use the sd function to compute the standard deviation of random_vector. Store the result in a variable called sd_vector.

[1] 331.3606

35.   Use the round function to round the values of random_vector. Store the result in a variable called round_vector.

[1] 200 685 917 284 105 701 528 808 957 110

36.   Use the sort function to sort the values of random_vector. Store the result in a variable called sort_vector.

[1] 104.6501 110.4530 200.2145 284.3995 527.9600 685.2186 701.0575 807.9352

[9] 916.8758 956.5001

37.   Consider the following code. Explain in a comment what you think the code is doing. Include the answer in your written report.

set.seed(5)

random_vector <- rnorm(n=1000, mean = 50, sd = 15)

38.   Use the hist function and provide it with random_vector. Explain the result in a comment. Include both the explanation and visualization in your report.

39.   Download the datafileds_salaries.csv from Canvas. Save it on your computer in the same folder (directory) where your .R file for this project is located.

40.   Using the p_load function, load the tidyverse set of libraries. Pacman will both install and load the tidyverse libraries.

p_load(tidyverse)

41.   The tidyverse has a function called read_csv to read files when you specify the filename. Store the result of the read into a variable called first_dataframe.

42.   Try each of the following blocks of code. Add a one-sentence comment describing

what you believe is happening. Include your answers in your written report.

head(first_dataframe)

head(first_dataframe, n = 7)

names(first_dataframe)

smaller_dataframe <- select(first_dataframe, job_title, salary_in_usd)

smaller_dataframe

better_smaller_dataframe <- arrange(smaller_dataframe,

desc(salary_in_usd))

better_smaller_dataframe

better_smaller_dataframe <- filter(smaller_dataframe, salary_in_usd > 80000)

better_smaller_dataframe

better_smaller_dataframe <-

mutate(smaller_dataframe, salary_in_euros = salary_in_usd * .94)

better_smaller_dataframe

better_smaller_dataframe <- slice(smaller_dataframe, 1, 1, 2, 3, 4, 10, 1)

better_smaller_dataframe

ggplot(better_smaller_dataframe) +

geom_col(mapping = aes(x = job_title, y = salary_in_usd), fill = "blue") +

xlab("Job Title") +

ylab("Salary in US Dollars") +

labs(title = "Comparison of Jobs ") +

scale y continuous(labels = scales::dollar) +

theme(axis.text.x = element_text(angle = 50, hjust = 1))

Submitting to Canvas

When you are satisfied with your solution, take the following steps:

1.     Remove any lines in your code with “install.packages.”

2.     Remove any lines in your code that use the view function.

3.      Submit two (2) files under the appropriate assignment in Canvas:

1.     Your R script named Lastname_Project1.R.

2.     A PDF of  your four-page report titled Lastname_Project1_Report.pdf.

Your report should contain the following information formatted as specified:

Title Page

Include your name, assignment title, and submission date.