Getting Started

]

# Week 1: .fancy[Getting Started]

### <svg aria-hidden="true" role="img" viewBox="0 0 512 512" style="height:1em;width:1em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:white;overflow:visible;position:relative;"><path d="M243.4 2.6l-224 96c-14 6-21.8 21-18.7 35.8S16.8 160 32 160v8c0 13.3 10.7 24 24 24H456c13.3 0 24-10.7 24-24v-8c15.2 0 28.3-10.7 31.3-25.6s-4.8-29.9-18.7-35.8l-224-96c-8-3.4-17.2-3.4-25.2 0zM128 224H64V420.3c-.6 .3-1.2 .7-1.8 1.1l-48 32c-11.7 7.8-17 22.4-12.9 35.9S17.9 512 32 512H480c14.1 0 26.5-9.2 30.6-22.7s-1.1-28.1-12.9-35.9l-48-32c-.6-.4-1.2-.7-1.8-1.1V224H384V416H344V224H280V416H232V224H168V416H128V224zM256 64a32 32 0 1 1 0 64 32 32 0 1 1 0-64z"/></svg> EMSE 4571 / 6571: Intro to Programming for Analytics
### <svg aria-hidden="true" role="img" viewBox="0 0 448 512" style="height:1em;width:0.88em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:white;overflow:visible;position:relative;"><path d="M304 128a80 80 0 1 0 -160 0 80 80 0 1 0 160 0zM96 128a128 128 0 1 1 256 0A128 128 0 1 1 96 128zM49.3 464H398.7c-8.9-63.3-63.3-112-129-112H178.3c-65.7 0-120.1 48.7-129 112zM0 482.3C0 383.8 79.8 304 178.3 304h91.4C368.2 304 448 383.8 448 482.3c0 16.4-13.3 29.7-29.7 29.7H29.7C13.3 512 0 498.7 0 482.3z"/></svg> John Paul Helveston
### <svg aria-hidden="true" role="img" viewBox="0 0 448 512" style="height:1em;width:0.88em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:white;overflow:visible;position:relative;"><path d="M152 24c0-13.3-10.7-24-24-24s-24 10.7-24 24V64H64C28.7 64 0 92.7 0 128v16 48V448c0 35.3 28.7 64 64 64H384c35.3 0 64-28.7 64-64V192 144 128c0-35.3-28.7-64-64-64H344V24c0-13.3-10.7-24-24-24s-24 10.7-24 24V64H152V24zM48 192H400V448c0 8.8-7.2 16-16 16H64c-8.8 0-16-7.2-16-16V192z"/></svg> January 18, 2024

]

---

# Week 1: .fancy[Getting Started]

### 1. Course orientation

### BREAK

### 2. Getting started with R & RStudio
### 3. Operators & data types
### 4. Preview of HW 1

---

# Week 1: .fancy[Getting Started]

### 1. .orange[Course orientation]

### BREAK

### 2. Getting started with R & RStudio
### 3. Operators & data types
### 4. Preview of HW 1

---

# Meet your instructor!

]]

### John Helveston, Ph.D.

Assistant Professor, Engineering Management & Systems Engineering

- 2016-2018 Postdoc at [Institute for Sustainable Energy](https://www.bu.edu/ise/), Boston University
- 2016 PhD in Engineering & Public Policy at Carnegie Mellon University
- 2015 MS in Engineering & Public Policy at Carnegie Mellon University
- 2010 BS in Engineering Science & Mechanics at Virginia Tech
- Website: [www.jhelvy.com](http://www.jhelvy.com/)

]]

---

# Meet your tutors!

]]

### **Lujin Zhao**

- Graduate Teaching Assistant (GTA)
- 4th Year PhD student in EMSE

]

---

# Meet your tutors!

]]

### **Bogdan Bunea**

- Learning Assistant (LA)
- EMSE Sophomore & P4A / EDA alumni

]

---

# Course orientation

## <svg aria-hidden="true" role="img" viewBox="0 0 512 512" style="height:1em;width:1em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M352 256c0 22.2-1.2 43.6-3.3 64H163.3c-2.2-20.4-3.3-41.8-3.3-64s1.2-43.6 3.3-64H348.7c2.2 20.4 3.3 41.8 3.3 64zm28.8-64H503.9c5.3 20.5 8.1 41.9 8.1 64s-2.8 43.5-8.1 64H380.8c2.1-20.6 3.2-42 3.2-64s-1.1-43.4-3.2-64zm112.6-32H376.7c-10-63.9-29.8-117.4-55.3-151.6c78.3 20.7 142 77.5 171.9 151.6zm-149.1 0H167.7c6.1-36.4 15.5-68.6 27-94.7c10.5-23.6 22.2-40.7 33.5-51.5C239.4 3.2 248.7 0 256 0s16.6 3.2 27.8 13.8c11.3 10.8 23 27.9 33.5 51.5c11.6 26 20.9 58.2 27 94.7zm-209 0H18.6C48.6 85.9 112.2 29.1 190.6 8.4C165.1 42.6 145.3 96.1 135.3 160zM8.1 192H131.2c-2.1 20.6-3.2 42-3.2 64s1.1 43.4 3.2 64H8.1C2.8 299.5 0 278.1 0 256s2.8-43.5 8.1-64zM194.7 446.6c-11.6-26-20.9-58.2-27-94.6H344.3c-6.1 36.4-15.5 68.6-27 94.6c-10.5 23.6-22.2 40.7-33.5 51.5C272.6 508.8 263.3 512 256 512s-16.6-3.2-27.8-13.8c-11.3-10.8-23-27.9-33.5-51.5zM135.3 352c10 63.9 29.8 117.4 55.3 151.6C112.2 482.9 48.6 426.1 18.6 352H135.3zm358.1 0c-30 74.1-93.6 130.9-171.9 151.6c25.5-34.2 45.2-87.7 55.3-151.6H493.4z"/></svg> Everything you need will be on the course website:

### https://p4a.seas.gwu.edu/2024-Spring/

---

## <svg aria-hidden="true" role="img" viewBox="0 0 512 512" style="height:1em;width:1em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M192 104.8c0-9.2-5.8-17.3-13.2-22.8C167.2 73.3 160 61.3 160 48c0-26.5 28.7-48 64-48s64 21.5 64 48c0 13.3-7.2 25.3-18.8 34c-7.4 5.5-13.2 13.6-13.2 22.8v0c0 12.8 10.4 23.2 23.2 23.2H336c26.5 0 48 21.5 48 48v56.8c0 12.8 10.4 23.2 23.2 23.2v0c9.2 0 17.3-5.8 22.8-13.2c8.7-11.6 20.7-18.8 34-18.8c26.5 0 48 28.7 48 64s-21.5 64-48 64c-13.3 0-25.3-7.2-34-18.8c-5.5-7.4-13.6-13.2-22.8-13.2v0c-12.8 0-23.2 10.4-23.2 23.2V464c0 26.5-21.5 48-48 48H279.2c-12.8 0-23.2-10.4-23.2-23.2v0c0-9.2 5.8-17.3 13.2-22.8c11.6-8.7 18.8-20.7 18.8-34c0-26.5-28.7-48-64-48s-64 21.5-64 48c0 13.3 7.2 25.3 18.8 34c7.4 5.5 13.2 13.6 13.2 22.8v0c0 12.8-10.4 23.2-23.2 23.2H48c-26.5 0-48-21.5-48-48V343.2C0 330.4 10.4 320 23.2 320v0c9.2 0 17.3 5.8 22.8 13.2C54.7 344.8 66.7 352 80 352c26.5 0 48-28.7 48-64s-21.5-64-48-64c-13.3 0-25.3 7.2-34 18.8C40.5 250.2 32.4 256 23.2 256v0C10.4 256 0 245.6 0 232.8V176c0-26.5 21.5-48 48-48H168.8c12.8 0 23.2-10.4 23.2-23.2v0z"/></svg> Course is broken into **two chunks**:

### 1. Programming (before Spring Break)
### 2. Analytics (after Spring Break)

<br>

### In the fall, you'll take EMSE 4572 / 6572: Exploratory Data Analysis

### [Fall 2023 Project Showcase](https://eda.seas.gwu.edu/showcase/2023-fall.html)

---

# Learning Objectives

<br>

## After this class, you will know how to...

### ...write <svg aria-hidden="true" role="img" viewBox="0 0 581 512" style="height:1em;width:1.13em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M581 226.6C581 119.1 450.9 32 290.5 32S0 119.1 0 226.6C0 322.4 103.3 402 239.4 418.1V480h99.1v-61.5c24.3-2.7 47.6-7.4 69.4-13.9L448 480h112l-67.4-113.7c54.5-35.4 88.4-84.9 88.4-139.7zm-466.8 14.5c0-73.5 98.9-133 220.8-133s211.9 40.7 211.9 133c0 50.1-26.5 85-70.3 106.4-2.4-1.6-4.7-2.9-6.4-3.7-10.2-5.2-27.8-10.5-27.8-10.5s86.6-6.4 86.6-92.7-90.6-87.9-90.6-87.9h-199V361c-74.1-21.5-125.2-67.1-125.2-119.9zm225.1 38.3v-55.6c57.8 0 87.8-6.8 87.8 27.3 0 36.5-38.2 28.3-87.8 28.3zm-.9 72.5H365c10.8 0 18.9 11.7 24 19.2-16.1 1.9-33 2.8-50.6 2.9v-22.1z"/></svg> code to solve medium-sized tasks.
### ...pro-actively test and debug code.
### ...import, export, manipulate, and visualize data.

---

# Attendance / Participation (7%)

<br>

### **Attendance will be taken** and will be part of your participation grade

---

# Homeworks (48% of grade)

<br>

---

# Late submissions

<br>

### - **3** late days - use them anytime, no questions asked
### - After that, 50% off for up to 24 hours after deadline, 0% afterwards
### - Contact me for special cases

---

# Quizzes (15% of grade)

<br>

> **Why quiz at all?** There's a phenomenon called the "retrieval effect" - basically, you have to _practice_ remembering things, otherwise your brain won't remember them (details in the book ["Make It Stick: The Science of Successful Learning"](https://www.hup.harvard.edu/catalog.php?isbn=9780674729018)).

---

# Exams (30% of grade)

<br>

---

# .center[Grades]

<br>

Component                  | Weight | Notes
---------------------------|--------|----------------
Participation / Attendance | 7%     |
Homeworks & Readings (13x) | 48%    | Lowest 1 dropped
Quizzes (7x)               | 15%    | Lowest 2 dropped
Midterm Exam               | 10%    |
Final Exam                 | 20%    |

---

# .center[Alternative Minimum Grade (AMG)]

- Designed for those who struggle early but work hard to succeed in 2nd half.
- Highest possible grade is "C"

<br>

Course Component   | Weight
-------------------|----
Best 10 Homeworks  | 40%
Best 4 Quizzes     | 10%
Midterm Exam       | 10%
Final Exam         | 40%

---

# Course policies

- ## BE NICE
- ## BE HONEST
- ## DON'T CHEAT

]

## **Don't copy-paste others' code!**

]

---

# [AI Policy](https://p4a.seas.gwu.edu/2024-Spring/syllabus.html#use-of-chatgpt-and-other-ai-tools)

### ([Demo](https://chat.openai.com/))

<br>

## Assignments 1-7:<br>**Not permitted**

]

## Assignments 8-13:<br>**Permitted, with caveats**

]

---

# How to succeed in this class

## <svg aria-hidden="true" role="img" viewBox="0 0 640 512" style="height:1em;width:1.25em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M144 0a80 80 0 1 1 0 160A80 80 0 1 1 144 0zM512 0a80 80 0 1 1 0 160A80 80 0 1 1 512 0zM0 298.7C0 239.8 47.8 192 106.7 192h42.7c15.9 0 31 3.5 44.6 9.7c-1.3 7.2-1.9 14.7-1.9 22.3c0 38.2 16.8 72.5 43.3 96c-.2 0-.4 0-.7 0H21.3C9.6 320 0 310.4 0 298.7zM405.3 320c-.2 0-.4 0-.7 0c26.6-23.5 43.3-57.8 43.3-96c0-7.6-.7-15-1.9-22.3c13.6-6.3 28.7-9.7 44.6-9.7h42.7C592.2 192 640 239.8 640 298.7c0 11.8-9.6 21.3-21.3 21.3H405.3zM224 224a96 96 0 1 1 192 0 96 96 0 1 1 -192 0zM128 485.3C128 411.7 187.7 352 261.3 352H378.7C452.3 352 512 411.7 512 485.3c0 14.7-11.9 26.7-26.7 26.7H154.7c-14.7 0-26.7-11.9-26.7-26.7z"/></svg> Participate during class!

## <svg aria-hidden="true" role="img" viewBox="0 0 512 512" style="height:1em;width:1em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M469.3 19.3l23.4 23.4c25 25 25 65.5 0 90.5l-56.4 56.4L322.3 75.7l56.4-56.4c25-25 65.5-25 90.5 0zM44.9 353.2L299.7 98.3 413.7 212.3 158.8 467.1c-6.7 6.7-15.1 11.6-24.2 14.2l-104 29.7c-8.4 2.4-17.4 .1-23.6-6.1s-8.5-15.2-6.1-23.6l29.7-104c2.6-9.2 7.5-17.5 14.2-24.2zM249.4 103.4L103.4 249.4 16 161.9c-18.7-18.7-18.7-49.1 0-67.9L94.1 16c18.7-18.7 49.1-18.7 67.9 0l19.8 19.8c-.3 .3-.7 .6-1 .9l-64 64c-6.2 6.2-6.2 16.4 0 22.6s16.4 6.2 22.6 0l64-64c.3-.3 .6-.7 .9-1l45.1 45.1zM408.6 262.6l45.1 45.1c-.3 .3-.7 .6-1 .9l-64 64c-6.2 6.2-6.2 16.4 0 22.6s16.4 6.2 22.6 0l64-64c.3-.3 .6-.7 .9-1L496 350.1c18.7 18.7 18.7 49.1 0 67.9L417.9 496c-18.7 18.7-49.1 18.7-67.9 0l-87.4-87.4L408.6 262.6z"/></svg> Start assignments early and **read carefully**!

## <svg aria-hidden="true" role="img" viewBox="0 0 640 512" style="height:1em;width:1.25em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M80 48a48 48 0 1 1 96 0A48 48 0 1 1 80 48zm64 193.7v65.1l51 51c7.1 7.1 11.8 16.2 13.4 26.1l15.2 90.9c2.9 17.4-8.9 33.9-26.3 36.8s-33.9-8.9-36.8-26.3l-14.3-85.9L66.8 320C54.8 308 48 291.7 48 274.7V186.6c0-32.4 26.2-58.6 58.6-58.6c24.1 0 46.5 12 59.9 32l47.4 71.1 10.1 5V160c0-17.7 14.3-32 32-32H384c17.7 0 32 14.3 32 32v76.2l10.1-5L473.5 160c13.3-20 35.8-32 59.9-32c32.4 0 58.6 26.2 58.6 58.6v88.1c0 17-6.7 33.3-18.7 45.3l-79.4 79.4-14.3 85.9c-2.9 17.4-19.4 29.2-36.8 26.3s-29.2-19.4-26.3-36.8l15.2-90.9c1.6-9.9 6.3-19 13.4-26.1l51-51V241.7l-19 28.5c-4.6 7-11 12.6-18.5 16.3l-59.6 29.8c-2.4 1.3-4.9 2.2-7.6 2.8c-2.6 .6-5.3 .9-7.9 .8H256.7c-2.5 .1-5-.2-7.5-.7c-2.9-.6-5.6-1.6-8.1-3l-59.5-29.8c-7.5-3.7-13.8-9.4-18.5-16.3l-19-28.5zM2.3 468.1L50.1 348.6l49.2 49.2-37.6 94c-6.6 16.4-25.2 24.4-41.6 17.8S-4.3 484.5 2.3 468.1zM512 0a48 48 0 1 1 0 96 48 48 0 1 1 0-96zm77.9 348.6l47.8 119.5c6.6 16.4-1.4 35-17.8 41.6s-35-1.4-41.6-17.8l-37.6-94 49.2-49.2z"/></svg> Ask for help!

---

# Getting Help

## <svg aria-hidden="true" role="img" viewBox="0 0 448 512" style="height:1em;width:0.88em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg> Use [Slack](https://emse-p4a-s24.slack.com/) to ask questions.

---

# <svg aria-hidden="true" role="img" viewBox="0 0 512 512" style="height:1em;width:1em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M64 80c-8.8 0-16 7.2-16 16V258c5.1-1.3 10.5-2 16-2H448c5.5 0 10.9 .7 16 2V96c0-8.8-7.2-16-16-16H64zM48 320v96c0 8.8 7.2 16 16 16H448c8.8 0 16-7.2 16-16V320c0-8.8-7.2-16-16-16H64c-8.8 0-16 7.2-16 16zM0 320V96C0 60.7 28.7 32 64 32H448c35.3 0 64 28.7 64 64V320v96c0 35.3-28.7 64-64 64H64c-35.3 0-64-28.7-64-64V320zm280 48a24 24 0 1 1 48 0 24 24 0 1 1 -48 0zm120-24a24 24 0 1 1 0 48 24 24 0 1 1 0-48z"/></svg> [Course Software](https://p4a.seas.gwu.edu/2024-Spring/software.html)

<br>

## <svg aria-hidden="true" role="img" viewBox="0 0 448 512" style="height:1em;width:0.88em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg> [Slack](https://emse-p4a-s24.slack.com/): Install app & **turn notifications on**!

## <svg aria-hidden="true" role="img" viewBox="0 0 581 512" style="height:1em;width:1.13em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M581 226.6C581 119.1 450.9 32 290.5 32S0 119.1 0 226.6C0 322.4 103.3 402 239.4 418.1V480h99.1v-61.5c24.3-2.7 47.6-7.4 69.4-13.9L448 480h112l-67.4-113.7c54.5-35.4 88.4-84.9 88.4-139.7zm-466.8 14.5c0-73.5 98.9-133 220.8-133s211.9 40.7 211.9 133c0 50.1-26.5 85-70.3 106.4-2.4-1.6-4.7-2.9-6.4-3.7-10.2-5.2-27.8-10.5-27.8-10.5s86.6-6.4 86.6-92.7-90.6-87.9-90.6-87.9h-199V361c-74.1-21.5-125.2-67.1-125.2-119.9zm225.1 38.3v-55.6c57.8 0 87.8-6.8 87.8 27.3 0 36.5-38.2 28.3-87.8 28.3zm-.9 72.5H365c10.8 0 18.9 11.7 24 19.2-16.1 1.9-33 2.8-50.6 2.9v-22.1z"/></svg> [R](https://cloud.r-project.org/) & [RStudio](https://posit.co/download/rstudio-desktop/): Install both.

## <svg aria-hidden="true" role="img" viewBox="0 0 581 512" style="height:1em;width:1.13em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M581 226.6C581 119.1 450.9 32 290.5 32S0 119.1 0 226.6C0 322.4 103.3 402 239.4 418.1V480h99.1v-61.5c24.3-2.7 47.6-7.4 69.4-13.9L448 480h112l-67.4-113.7c54.5-35.4 88.4-84.9 88.4-139.7zm-466.8 14.5c0-73.5 98.9-133 220.8-133s211.9 40.7 211.9 133c0 50.1-26.5 85-70.3 106.4-2.4-1.6-4.7-2.9-6.4-3.7-10.2-5.2-27.8-10.5-27.8-10.5s86.6-6.4 86.6-92.7-90.6-87.9-90.6-87.9h-199V361c-74.1-21.5-125.2-67.1-125.2-119.9zm225.1 38.3v-55.6c57.8 0 87.8-6.8 87.8 27.3 0 36.5-38.2 28.3-87.8 28.3zm-.9 72.5H365c10.8 0 18.9 11.7 24 19.2-16.1 1.9-33 2.8-50.6 2.9v-22.1z"/></svg> [RStudio Cloud](https://posit.cloud/plans/free): A (free) web-based version of RStudio.

---

# .fancy[Intermission]

---

# Week 1: .fancy[Getting Started]

### 1. Course orientation

### BREAK

### 2. .orange[Getting started with R & RStudio]
### 3. Operators & data types
### 4. Preview of HW 1

---

## What is <svg aria-hidden="true" role="img" viewBox="0 0 581 512" style="height:1em;width:1.13em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M581 226.6C581 119.1 450.9 32 290.5 32S0 119.1 0 226.6C0 322.4 103.3 402 239.4 418.1V480h99.1v-61.5c24.3-2.7 47.6-7.4 69.4-13.9L448 480h112l-67.4-113.7c54.5-35.4 88.4-84.9 88.4-139.7zm-466.8 14.5c0-73.5 98.9-133 220.8-133s211.9 40.7 211.9 133c0 50.1-26.5 85-70.3 106.4-2.4-1.6-4.7-2.9-6.4-3.7-10.2-5.2-27.8-10.5-27.8-10.5s86.6-6.4 86.6-92.7-90.6-87.9-90.6-87.9h-199V361c-74.1-21.5-125.2-67.1-125.2-119.9zm225.1 38.3v-55.6c57.8 0 87.8-6.8 87.8 27.3 0 36.5-38.2 28.3-87.8 28.3zm-.9 72.5H365c10.8 0 18.9 11.7 24 19.2-16.1 1.9-33 2.8-50.6 2.9v-22.1z"/></svg>? ([Read a brief history here](https://bookdown.org/rdpeng/rprogdatascience/history-and-overview-of-r.html))

Chambers creates "S" (1976, Bell Labs)<br>
Ross & Robert create "R" (1991, U. of Auckland)

## .center[[John Chambers](https://en.wikipedia.org/wiki/John_Chambers_(statistician)]

]

## .center[[Ross Ihaka](https://en.wikipedia.org/wiki/Ross_Ihaka)]

]

## .center[[Robert Gentleman](https://en.wikipedia.org/wiki/Robert_Gentleman_(statistician)]

]

---

# Wait, why aren't we using Python?

- [Python](https://en.wikipedia.org/wiki/Python_(programming_language) is a general purpose language developed by [**Guido van Rossum**](https://en.wikipedia.org/wiki/Guido_van_Rossum), a computer scientist.
- Unlike R, Python was not originally developed for data analysis.
- Both languages are extremely useful, and you should learn python too.

]

]

---

## What is RStudio?

]

]

---

# RStudio Orientation

## Open this

]

## Not this

]

---

# RStudio Orientation

]

- Know the boxes
- Customize the layout
- Customize the look
- [Extra themes](https://github.com/gadenbuie/rsthemes)

]

---

# Your first conveRsation

### Write stuff in the console, then press "enter"

Example: **addition**

```r
3 + 4
```

```
#> [1] 7
```

Example: **error**

```r
3 + "4"
```

```
#> Error in 3 + "4": non-numeric argument to binary operator
```

---

# Storing values

### Use the "`<-`" symbol to assign _values_ to _objects_

```r
x <- 40
x
```

```
#> [1] 40
```

```r
x + 2
```

```
#> [1] 42
```

---

# Storing values

### If you overwrite an object, R "forgets" the old value

Example:

```r
x <- 42
x
```

```
#> [1] 42
```

```r
x <- 50
x
```

```
#> [1] 50
```

---

# Storing values

<br>

### You can also use the `=` symbol to assign values

```r
x = 50
x
```

```
#> [1] 50
```

### ...but you should use `<-`

---

# Storing values

### **Pro tip 1**:

### Shortcut for `<-` symbol

|OS | Shortcut
|:--|:--------
|mac | `option` + `-`
|windows | `alt` + `-`

]

(see [here](https://support.rstudio.com/hc/en-us/articles/200711853-Keyboard-Shortcuts) for more shortcuts)

]

### **Pro tip 2**:

### Always surround `<-` with spaces

Example:

```r
x<-2
```

Does this mean `x <- 2` or `x < -2`?

]

---

# Storing values

### You can store more than just numbers

```r
x <- "If you want to view paradise"
y <- "simply look around and view it"
```

```r
x
```

```
#> [1] "If you want to view paradise"
```

```r
y
```

```
#> [1] "simply look around and view it"
```

---

## R ignores **extra space**

```r
x     <-       2
y  <-            3
z        <- 4
```

Check:

```r
x
```

```
#> [1] 2
```

```r
y
```

```
#> [1] 3
```

```r
z
```

```
#> [1] 4
```

]

## R cares about **casing**

```r
number <- 2
Number <- 3
numbeR <- 4
```

Check:

```r
number
```

```
#> [1] 2
```

```r
Number
```

```
#> [1] 3
```

```r
numbeR
```

```
#> [1] 4
```

]

---

# Use `#` for comments

### R ignores everything after the `#` symbol

Example:

```r
speed <- 42 # This is mph, not km/h
speed
```

```
#> [1] 42
```

---

# Use meaningful variable names

**Example**: You are recording the speed of a car in mph

**Poor** variable name:

```r
x <- 42
```

**Good** variable name:

```r
speed <- 42
```

**Even better** variable name:

```r
speed_mph <- 42
```

---

# Use standard casing styles

<center>
<img src="images/horst_casing.jpg" width=700>
</center>
Art by [Allison Horst](https://github.com/allisonhorst/stats-illustrations)

---

# Use standard casing styles

<img src="images/horst_casing.jpg" width=600> Art by [Allison Horst](https://github.com/allisonhorst/stats-illustrations)

]

I recommend using one of these:

- `snake_case_uses_underscores`
- `camelCaseUsesCaps`

Example:

```r
days_in_week <- 7
monthsInYear <- 12
```

]

---

## The workspace

View all the current objects:

```r
objects()
```

```
#>  [1] "class"          "days_in_week"   "from"           "input"          "monthsInYear"   "number"         "numbeR"         "Number"         "output_file"    "path_notes"     "path_pdf"       "path_slides"    "proc"           "render_args"   
#> [15] "render_fn"      "root"           "self_contained" "speed"          "speed_mph"      "to"             "x"              "y"              "z"
```

]

Remove an object by name:

```r
rm(class)
objects()
```

```
#>  [1] "days_in_week"   "from"           "input"          "monthsInYear"   "number"         "numbeR"         "Number"         "output_file"    "path_notes"     "path_pdf"       "path_slides"    "proc"           "render_args"    "render_fn"     
#> [15] "root"           "self_contained" "speed"          "speed_mph"      "to"             "x"              "y"              "z"
```

]

---

# View prior code in history pane

# Use "up" arrow see previous code

---

# Staying organized

## 1) Save your code in .R files

> ### File > New File > R Script

## 2) Keep work in R Project files

> ### File > New Project...

---

## Your turn

### A. Practice getting organized

1. Open RStudio and create a new R project called `week1`.
2. Create a new R script and save it as `practice.R`.
3. Open the `practice.R` file and write your answers to these questions in it.

]]

### B. Creating & working with objects

1) Create objects to store the values in this table:

| City              | Area (sq mi) | Population (thousands) |
|-------------------|----------------|------------------------|
| San Francisco, CA | 47             | 884                    |
| Chicago, IL       | 228            | 2,716                  |
| Washington, DC    | 61             | 694                    |

2) Using the objects you created, answer the following questions:

- Which city has the highest density?
  - How many _more_ people would need to live in DC for it to have the same population density as San Francisco?

]]

---

# Week 1: .fancy[Getting Started]

### 1. Course orientation

### BREAK

### 2. Getting started with R & RStudio
### 3. .orange[Operators & data types]
### 4. Preview of HW 1

---

# R as a calculator

## Basic operators:

### - Addition: `+`
### - Subtraction: `-`
### - Multiplication: `*`
### - Division: `/`

]

## Other important operators:

### - Power: `^`
### - Integer Division: `%/%`
### - Modulus: `%%`

]

---

# Integer division: `%/%`

Integer division drops the remainder from regular division

```r
4 / 3 # Regular division
```

```
#> [1] 1.333333
```

```r
4 %/% 3 # Integer division
```

```
#> [1] 1
```

---

# Integer division: `%/%`

Integer division drops the remainder from regular division

What will this return?

```r
4 %/% 4
```

```
#> [1] 1
```

What will this return?

```r
4 %/% 5
```

```
#> [1] 0
```

---

# Modulus operator: `%%`

Modulus returns the _remainder_ after doing division

```r
5 %% 3
```

```
#> [1] 2
```

```r
3.1415 %% 3
```

```
#> [1] 0.1415
```

---

# Modulus operator: `%%`

Modulus returns the _remainder_ after doing division

What will this return?

```r
4 %% 4
```

```
#> [1] 0
```

What will this return?

```r
4 %% 5
```

```
#> [1] 4
```

---

## Odds and evens with `n %% 2`

If `n %% 2` is `0`, `n` is **EVEN**

```r
10 %% 2
```

```
#> [1] 0
```

```r
12 %% 2
```

```
#> [1] 0
```

Also works with negative numbers!

```r
-42 %% 2
```

```
#> [1] 0
```

]

If `n %% 2` is `1`, `n` is **ODD**

```r
1 %% 2
```

```
#> [1] 1
```

```r
13 %% 2
```

```
#> [1] 1
```

Also works with negative numbers!

```r
-47 %% 2
```

```
#> [1] 1
```

]

---

## Number "chopping" with 10s

The mod operator (`%%`) "chops" a number and returns everything to the _right_

```r
123456 %% 1
```

```
#> [1] 0
```

```r
123456 %% 10
```

```
#> [1] 6
```

```r
123456 %% 100
```

```
#> [1] 56
```

]

Integer division (`%/%`) "chops" a number and returns everything to the _left_

```r
123456 %/% 1
```

```
#> [1] 123456
```

```r
123456 %/% 10
```

```
#> [1] 12345
```

```r
123456 %/% 100
```

```
#> [1] 1234
```

]

---

## Number "chopping" with 10s

- `%%` returns everything to the _right_ (`"chop" ->`)
- `%/%` returns everything to the _left_ (`<- "chop"`)
- The "chop" point is always just to the _right_ of the chopping digit

<br>

<div style="width:1000px">
<table class="table table-condensed">
<thead>
<tr class="header">
<th>Example</th>
<th>“Chop” point</th>
<th></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td><code>1234 %% 1</code></td>
<td><code>1234 |</code></td>
<td>Right of the <code>1</code>’s digit</td>
</tr>
<tr class="even">
<td><code>1234 %% 10</code></td>
<td><code>123 | 4</code></td>
<td>Right of the <code>10</code>’s digit</td>
</tr>
<tr class="odd">
<td><code>1234 %% 100</code></td>
<td><code>12 | 34</code></td>
<td>Right of the <code>100</code>’s digit</td>
</tr>
<tr class="even">
<td><code>1234 %% 1000</code></td>
<td><code>1 | 234</code></td>
<td>Right of the <code>1,000</code>’s digit</td>
</tr>
<tr class="odd">
<td><code>1234 %% 10000</code></td>
<td><code>| 1234</code></td>
<td>Right of the <code>10,000</code>’s digit</td>
</tr>
</tbody>
</table>
</div>

---

# Comparing things: **Relational operators**

### Compare if condition is `TRUE` or `FALSE` using:

- Less than: `<`
- Less than or equal to : `<=`
- Greater than or equal to: `>=`
- Greater than: `>`
- Equal: `==`
- Not equal: `!=`

]

```r
2 < 2
```

```
#> [1] FALSE
```

```r
2 <= 2
```

```
#> [1] TRUE
```

```r
(2 + 2) == 4
```

```
#> [1] TRUE
```

```r
(2 + 2) != 4
```

```
#> [1] FALSE
```

```r
"penguin" == "penguin"
```

```
#> [1] TRUE
```

]]

---

# Comparing things: **Logical operators**

<br>

### Make multiple comparisons with:

### - And: `&`
### - Or: `|`
### - Not: `!`

---

# Comparing things: **Logical operators**

With "and" (`&`), every part must be `TRUE`, otherwise the whole statement is `FALSE`:

```r
(2 == 2) & (3 == 3)
```

```
#> [1] TRUE
```

```r
(2 == 2) & (2 == 3)
```

```
#> [1] FALSE
```

]

With "or" (`|`), if _any_ part is `TRUE`, the whole statement is `TRUE`:

```r
(2 == 2) | (3 == 3)
```

```
#> [1] TRUE
```

```r
(2 == 2) | (2 == 3)
```

```
#> [1] TRUE
```

]

---

# Comparing things: **Logical operators**

The "not" (`!`) symbol produces the _opposite_ statement:

```r
! (2 == 2)
```

```
#> [1] FALSE
```

```r
! (2 == 2) | (3 == 3)
```

```
#> [1] TRUE
```

```r
! ((2 == 2) | (3 == 3))
```

```
#> [1] FALSE
```

---

# Comparing things: **Logical operators**

### Order precedence for logical operators: `! > & > |`

```r
TRUE | FALSE & FALSE
```

```
#> [1] TRUE
```

```r
(TRUE | FALSE) & FALSE
```

```
#> [1] FALSE
```

]

```r
! TRUE | TRUE
```

```
#> [1] TRUE
```

```r
! (TRUE | TRUE)
```

```
#> [1] FALSE
```

]

---

# Comparing things: **Logical operators**

### **Pro tip**: Use parentheses

```r
! 3 == 5   # Confusing
```

```
#> [1] TRUE
```

```r
! (3 == 5) # Less confusing
```

```
#> [1] TRUE
```

]

---

## Other important points

### R follows BEDMAS:

1. **B**rackets
2. **E**xponents
3. **D**ivision
4. **M**ultiplication
5. **A**ddition
6. **S**ubtraction

]

### **Pro tip**: Use parentheses

```r
1 + 2 * 4   # Confusing
```

```
#> [1] 9
```

```r
1 + (2 * 4) # Less confusing
```

```
#> [1] 9
```

]

---

# Your turn

Consider the following objects:

```r
w <- TRUE
x <- FALSE
y <- TRUE
```

Write code to answer the following questions:
1. Fill in _relational_ operators to make the following statement return `TRUE`:

`! (w __ x) & ! (y __ x)`

2. Fill in _logical_ operators to make this statement return `FALSE`:

`! (w __ x) | (y __ x)`

---

# Data Types

|Type      | Description                 | Example
|:---------|:----------------------------|:---------
|`double`   | Numbers w/decimals (aka "float") | `3.14`
|`integer`   | Numbers w/out decimals    | `42`
|`character` | Text (aka "string") | `"this is some text"`
|`logical`   | Used for comparing objects | `TRUE`, `FALSE`

---

## Use `typeof()` to find the type

```r
typeof(2)
```

```
#> [1] "double"
```

```r
typeof("hello")
```

```
#> [1] "character"
```

```r
typeof(TRUE)
```

```
#> [1] "logical"
```

---

# Numeric types (there are 2)

## Integers

### No decimals (e.g. `7`)

]

## Doubles (aka "float")

### Decimals (e.g. `7.0`)

]

---

## In R, numbers are "doubles" by default

```r
typeof(3)
```

```
#> [1] "double"
```

### R assumes that `3` is really `3.0`

### Make it an integer by adding `L`:

```r
typeof(3L)
```

```
#> [1] "integer"
```

---

# Character types

### Use single or double quotes around anything:

```r
typeof('hello')
```

```
#> [1] "character"
```

```r
typeof("3")
```

```
#> [1] "character"
```

Use single / double quotes if the string _contains_ a quote symbol:

```r
typeof("don't")
```

```
#> [1] "character"
```

---

# Logical types

Logical data only have two values:<br>`TRUE` or `FALSE`

```r
typeof(TRUE)
```

```
#> [1] "logical"
```

```r
typeof(FALSE)
```

```
#> [1] "logical"
```

]

Note that these have to be in all caps,<br>and **not** in quotes:

```r
typeof('TRUE')
```

```
#> [1] "character"
```

```r
typeof(True)
```

```
#> Error in typeof(True): object 'True' not found
```

]

---

# Logical types

Use to answer questions about logical statements.

Example: Is `1` greater than `2`?

```r
1 > 2
```

```
#> [1] FALSE
```

Example: Is `2` greater than `1`?

```r
1 < 2
```

```
#> [1] TRUE
```

---

## Special values

`Inf`: Infinity (_or really big numbers_)

```r
1/0
```

```
#> [1] Inf
```

`NaN`: Not a Number

```r
0/0
```

```
#> [1] NaN
```

`NA`: Not available (_value is missing_)

`NULL`: no value whatsoever

---

# Your turn

## Will these return `TRUE` or `FALSE`?

## (try to answer first, then run the code to check)

- `! typeof('3') == typeof(3)`
- `(typeof(7) != typeof("FALSE")) | FALSE`
- `! (typeof(TRUE) == typeof(FALSE)) & FALSE`

---

# Week 1: .fancy[Getting Started]

### 1. Course orientation

### BREAK

### 2. Getting started with R & RStudio
### 3. Operators & data types
### 4. .orange[Preview of HW 1]

---

# Go to the [schedule](https://p4a.seas.gwu.edu/2024-Spring/schedule.html)

# ...and read carefully!