Getting Started

.leftcol30[
<center>
<img src="https://github.com/emse-p4a-gwu/emse-p4a-gwu.github.io/raw/master/images/p4a_hex_sticker.png" width=250>
</center>
]

### <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="M496 128v16a8 8 0 0 1-8 8h-24v12c0 6.627-5.373 12-12 12H60c-6.627 0-12-5.373-12-12v-12H24a8 8 0 0 1-8-8v-16a8 8 0 0 1 4.941-7.392l232-88a7.996 7.996 0 0 1 6.118 0l232 88A8 8 0 0 1 496 128zm-24 304H40c-13.255 0-24 10.745-24 24v16a8 8 0 0 0 8 8h464a8 8 0 0 0 8-8v-16c0-13.255-10.745-24-24-24zM96 192v192H60c-6.627 0-12 5.373-12 12v20h416v-20c0-6.627-5.373-12-12-12h-36V192h-64v192h-64V192h-64v192h-64V192H96z"/></svg> EMSE 4571: 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="M224 256c70.7 0 128-57.3 128-128S294.7 0 224 0 96 57.3 96 128s57.3 128 128 128zm89.6 32h-16.7c-22.2 10.2-46.9 16-72.9 16s-50.6-5.8-72.9-16h-16.7C60.2 288 0 348.2 0 422.4V464c0 26.5 21.5 48 48 48h352c26.5 0 48-21.5 48-48v-41.6c0-74.2-60.2-134.4-134.4-134.4z"/></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="M0 464c0 26.5 21.5 48 48 48h352c26.5 0 48-21.5 48-48V192H0v272zm320-196c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zm0 128c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zM192 268c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zm0 128c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zM64 268c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12H76c-6.6 0-12-5.4-12-12v-40zm0 128c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12H76c-6.6 0-12-5.4-12-12v-40zM400 64h-48V16c0-8.8-7.2-16-16-16h-32c-8.8 0-16 7.2-16 16v48H160V16c0-8.8-7.2-16-16-16h-32c-8.8 0-16 7.2-16 16v48H48C21.5 64 0 85.5 0 112v48h448v-48c0-26.5-21.5-48-48-48z"/></svg> January 13, 2022
]

---

# 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!

.leftcol30[.circle[
<img src="https://p4a.seas.gwu.edu/2020-Fall/images/helveston.jpg" width="300">
]]
.rightcol70[

### John Helveston, Ph.D.

- 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!

- Graduate Assistant (GA)
- PhD student in EMSE
]

---

# Meet your tutors!

- Learning Assistant (LA) 
- EMSE Junior & P4A alumni (Fall 2020)
]

---

# Course orientation

## <svg aria-hidden="true" role="img" viewBox="0 0 496 512" style="height:1em;width:0.97em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M336.5 160C322 70.7 287.8 8 248 8s-74 62.7-88.5 152h177zM152 256c0 22.2 1.2 43.5 3.3 64h185.3c2.1-20.5 3.3-41.8 3.3-64s-1.2-43.5-3.3-64H155.3c-2.1 20.5-3.3 41.8-3.3 64zm324.7-96c-28.6-67.9-86.5-120.4-158-141.6 24.4 33.8 41.2 84.7 50 141.6h108zM177.2 18.4C105.8 39.6 47.8 92.1 19.3 160h108c8.7-56.9 25.5-107.8 49.9-141.6zM487.4 192H372.7c2.1 21 3.3 42.5 3.3 64s-1.2 43-3.3 64h114.6c5.5-20.5 8.6-41.8 8.6-64s-3.1-43.5-8.5-64zM120 256c0-21.5 1.2-43 3.3-64H8.6C3.2 212.5 0 233.8 0 256s3.2 43.5 8.6 64h114.6c-2-21-3.2-42.5-3.2-64zm39.5 96c14.5 89.3 48.7 152 88.5 152s74-62.7 88.5-152h-177zm159.3 141.6c71.4-21.2 129.4-73.7 158-141.6h-108c-8.8 56.9-25.6 107.8-50 141.6zM19.3 352c28.6 67.9 86.5 120.4 158 141.6-24.4-33.8-41.2-84.7-50-141.6h-108z"/></svg> Everything you need will be on the course website:

### https://p4a.seas.gwu.edu/2022-Spring/

## <svg aria-hidden="true" role="img" viewBox="0 0 576 512" style="height:1em;width:1.12em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M519.442 288.651c-41.519 0-59.5 31.593-82.058 31.593C377.409 320.244 432 144 432 144s-196.288 80-196.288-3.297c0-35.827 36.288-46.25 36.288-85.985C272 19.216 243.885 0 210.539 0c-34.654 0-66.366 18.891-66.366 56.346 0 41.364 31.711 59.277 31.711 81.75C175.885 207.719 0 166.758 0 166.758v333.237s178.635 41.047 178.635-28.662c0-22.473-40-40.107-40-81.471 0-37.456 29.25-56.346 63.577-56.346 33.673 0 61.788 19.216 61.788 54.717 0 39.735-36.288 50.158-36.288 85.985 0 60.803 129.675 25.73 181.23 25.73 0 0-34.725-120.101 25.827-120.101 35.962 0 46.423 36.152 86.308 36.152C556.712 416 576 387.99 576 354.443c0-34.199-18.962-65.792-56.558-65.792z"/></svg> Course is broken into **two chunks**:

### 1. Programming
### 2. Analytics

---

# 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.
### ...reproducibly import, export, manipulate, and visualize data.

---

# Homeworks (55% of grade)

## <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="M0 464c0 26.5 21.5 48 48 48h352c26.5 0 48-21.5 48-48V192H0v272zm320-196c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zm0 128c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zM192 268c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zm0 128c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12h-40c-6.6 0-12-5.4-12-12v-40zM64 268c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12H76c-6.6 0-12-5.4-12-12v-40zm0 128c0-6.6 5.4-12 12-12h40c6.6 0 12 5.4 12 12v40c0 6.6-5.4 12-12 12H76c-6.6 0-12-5.4-12-12v-40zM400 64h-48V16c0-8.8-7.2-16-16-16h-32c-8.8 0-16 7.2-16 16v48H160V16c0-8.8-7.2-16-16-16h-32c-8.8 0-16 7.2-16 16v48H48C21.5 64 0 85.5 0 112v48h448v-48c0-26.5-21.5-48-48-48z"/></svg> ~Every week (12 total)

## <svg aria-hidden="true" role="img" viewBox="0 0 576 512" style="height:1em;width:1.12em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M569.517 440.013C587.975 472.007 564.806 512 527.94 512H48.054c-36.937 0-59.999-40.055-41.577-71.987L246.423 23.985c18.467-32.009 64.72-31.951 83.154 0l239.94 416.028zM288 354c-25.405 0-46 20.595-46 46s20.595 46 46 46 46-20.595 46-46-20.595-46-46-46zm-43.673-165.346l7.418 136c.347 6.364 5.609 11.346 11.982 11.346h48.546c6.373 0 11.635-4.982 11.982-11.346l7.418-136c.375-6.874-5.098-12.654-11.982-12.654h-63.383c-6.884 0-12.356 5.78-11.981 12.654z"/></svg> **Don't abuse this flexibility**

## Two hard deadlines on homework submissions:

### 1. Mar. 10 (HWs 1-7)
### 2. May. 05 (HWs 8-12)

---

# Late submissions

<br>

### - **5** late days - use them anytime, no questions asked
### - No more than **2** late days on any one assignment
### - Contact me for special cases (I'm expecting a lot of these)

---

# Quizzes (15% of grade)

## <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="M139.61 35.5a12 12 0 0 0-17 0L58.93 98.81l-22.7-22.12a12 12 0 0 0-17 0L3.53 92.41a12 12 0 0 0 0 17l47.59 47.4a12.78 12.78 0 0 0 17.61 0l15.59-15.62L156.52 69a12.09 12.09 0 0 0 .09-17zm0 159.19a12 12 0 0 0-17 0l-63.68 63.72-22.7-22.1a12 12 0 0 0-17 0L3.53 252a12 12 0 0 0 0 17L51 316.5a12.77 12.77 0 0 0 17.6 0l15.7-15.69 72.2-72.22a12 12 0 0 0 .09-16.9zM64 368c-26.49 0-48.59 21.5-48.59 48S37.53 464 64 464a48 48 0 0 0 0-96zm432 16H208a16 16 0 0 0-16 16v32a16 16 0 0 0 16 16h288a16 16 0 0 0 16-16v-32a16 16 0 0 0-16-16zm0-320H208a16 16 0 0 0-16 16v32a16 16 0 0 0 16 16h288a16 16 0 0 0 16-16V80a16 16 0 0 0-16-16zm0 160H208a16 16 0 0 0-16 16v32a16 16 0 0 0 16 16h288a16 16 0 0 0 16-16v-32a16 16 0 0 0-16-16z"/></svg> [Example quiz](https://p4aquizdemo.formr.org/)

> **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
---------------------------|--------|----------------
Homeworks & Readings (12x) | 55%    | 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

> "Plagiarism is trying to pass someone else's work off as your own. Copying is about reverse-engineering."
>
> .right[-- Austin Kleon, from [Steal Like An Artist](https://austinkleon.com/steal/)&ensp;]
]

---

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

---

# How to succeed in this 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="M109.46 244.04l134.58-134.56-44.12-44.12-61.68 61.68a7.919 7.919 0 0 1-11.21 0l-11.21-11.21c-3.1-3.1-3.1-8.12 0-11.21l61.68-61.68-33.64-33.65C131.47-3.1 111.39-3.1 99 9.29L9.29 99c-12.38 12.39-12.39 32.47 0 44.86l100.17 100.18zm388.47-116.8c18.76-18.76 18.75-49.17 0-67.93l-45.25-45.25c-18.76-18.76-49.18-18.76-67.95 0l-46.02 46.01 113.2 113.2 46.02-46.03zM316.08 82.71l-297 296.96L.32 487.11c-2.53 14.49 10.09 27.11 24.59 24.56l107.45-18.84L429.28 195.9 316.08 82.71zm186.63 285.43l-33.64-33.64-61.68 61.68c-3.1 3.1-8.12 3.1-11.21 0l-11.21-11.21c-3.09-3.1-3.09-8.12 0-11.21l61.68-61.68-44.14-44.14L267.93 402.5l100.21 100.2c12.39 12.39 32.47 12.39 44.86 0l89.71-89.7c12.39-12.39 12.39-32.47 0-44.86z"/></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="M128 96c26.5 0 48-21.5 48-48S154.5 0 128 0 80 21.5 80 48s21.5 48 48 48zm384 0c26.5 0 48-21.5 48-48S538.5 0 512 0s-48 21.5-48 48 21.5 48 48 48zm125.7 372.1l-44-110-41.1 46.4-2 18.2 27.7 69.2c5 12.5 17 20.1 29.7 20.1 4 0 8-.7 11.9-2.3 16.4-6.6 24.4-25.2 17.8-41.6zm-34.2-209.8L585 178.1c-4.6-20-18.6-36.8-37.5-44.9-18.5-8-39-6.7-56.1 3.3-22.7 13.4-39.7 34.5-48.1 59.4L432 229.8 416 240v-96c0-8.8-7.2-16-16-16H240c-8.8 0-16 7.2-16 16v96l-16.1-10.2-11.3-33.9c-8.3-25-25.4-46-48.1-59.4-17.2-10-37.6-11.3-56.1-3.3-18.9 8.1-32.9 24.9-37.5 44.9l-18.4 80.2c-4.6 20 .7 41.2 14.4 56.7l67.2 75.9 10.1 92.6C130 499.8 143.8 512 160 512c1.2 0 2.3-.1 3.5-.2 17.6-1.9 30.2-17.7 28.3-35.3l-10.1-92.8c-1.5-13-6.9-25.1-15.6-35l-43.3-49 17.6-70.3 6.8 20.4c4.1 12.5 11.9 23.4 24.5 32.6l51.1 32.5c4.6 2.9 12.1 4.6 17.2 5h160c5.1-.4 12.6-2.1 17.2-5l51.1-32.5c12.6-9.2 20.4-20 24.5-32.6l6.8-20.4 17.6 70.3-43.3 49c-8.7 9.9-14.1 22-15.6 35l-10.1 92.8c-1.9 17.6 10.8 33.4 28.3 35.3 1.2.1 2.3.2 3.5.2 16.1 0 30-12.1 31.8-28.5l10.1-92.6 67.2-75.9c13.6-15.5 19-36.7 14.4-56.7zM46.3 358.1l-44 110c-6.6 16.4 1.4 35 17.8 41.6 16.8 6.6 35.1-1.7 41.6-17.8l27.7-69.2-2-18.2-41.1-46.4z"/></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-s22.slack.com/) to ask questions.

- Mondays from 8:00am - 2:00pm
- Wednesdays from 2:00 - 5:00pm
- Fridays from 12:00 - 2:00pm

---

# <svg aria-hidden="true" role="img" viewBox="0 0 576 512" style="height:1em;width:1.12em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M576 304v96c0 26.51-21.49 48-48 48H48c-26.51 0-48-21.49-48-48v-96c0-26.51 21.49-48 48-48h480c26.51 0 48 21.49 48 48zm-48-80a79.557 79.557 0 0 1 30.777 6.165L462.25 85.374A48.003 48.003 0 0 0 422.311 64H153.689a48 48 0 0 0-39.938 21.374L17.223 230.165A79.557 79.557 0 0 1 48 224h480zm-48 96c-17.673 0-32 14.327-32 32s14.327 32 32 32 32-14.327 32-32-14.327-32-32-32zm-96 0c-17.673 0-32 14.327-32 32s14.327 32 32 32 32-14.327 32-32-14.327-32-32-32z"/></svg> [Course Software](https://p4a.seas.gwu.edu/2022-Spring/ref-course-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-s22.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://rstudio.com/products/rstudio/download/): 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://rstudio.cloud/plans/free): A web-based version of RStudio.

---

# .fancy[Break]

## <svg aria-hidden="true" role="img" viewBox="0 0 576 512" style="height:1em;width:1.12em;vertical-align:-0.125em;margin-left:auto;margin-right:auto;font-size:inherit;fill:currentColor;overflow:visible;position:relative;"><path d="M576 304v96c0 26.51-21.49 48-48 48H48c-26.51 0-48-21.49-48-48v-96c0-26.51 21.49-48 48-48h480c26.51 0 48 21.49 48 48zm-48-80a79.557 79.557 0 0 1 30.777 6.165L462.25 85.374A48.003 48.003 0 0 0 422.311 64H153.689a48 48 0 0 0-39.938 21.374L17.223 230.165A79.557 79.557 0 0 1 48 224h480zm-48 96c-17.673 0-32 14.327-32 32s14.327 32 32 32 32-14.327 32-32-14.327-32-32-32zm-96 0c-17.673 0-32 14.327-32 32s14.327 32 32 32 32-14.327 32-32-14.327-32-32-32z"/></svg> Install [course software](https://p4a.seas.gwu.edu/2022-Spring/ref-course-software.html) if you haven't

---

# 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)

.cols3[
## .center[[John Chambers](https://en.wikipedia.org/wiki/John_Chambers_(statistician)]
<center>
<img src="https://datascience.stanford.edu/sites/g/files/sbiybj18491/f/styles/large-square/public/john-chambers.png?itok=o9PvzKwG" width=280>
</center>
]

.cols3[
## .center[[Ross Ihaka](https://en.wikipedia.org/wiki/Ross_Ihaka)]
<center>
<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Ross_Ihaka_%285189180796%29.jpg/1280px-Ross_Ihaka_%285189180796%29.jpg" width=100%>
</center>
]

.cols3[
## .center[[Robert Gentleman](https://en.wikipedia.org/wiki/Robert_Gentleman_(statistician)]
<center>
<img src="https://upload.wikimedia.org/wikipedia/commons/c/c6/Rober_Gentleman.png" width=250>
</center>
]

---

.leftcol[
## <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>
<center>
<img src="images/engine.jpg" width=500>
</center>
]

.rightcol[
## <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>Studio
<center>
<img src="images/dashboard.jpg" width=600>
</center>
]

---

# RStudio Orientation

---

# RStudio Orientation

.rightcol30[
- 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"

&zwj;Example: **addition**

```r
3 + 4
```

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

&zwj;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

&zwj;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 it's more R-like to use `<-`)

---

# 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"
```

---

# Storing values

### 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)
]

### Always surround `<-` with spaces

Example:

```r
x<-2
```

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

---

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

Check:

```r
x
```

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

```r
y
```

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

```r
z
```

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

```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

.leftcol60[
<img src="images/horst_casing.jpg" width=600> Art by [Allison Horst](https://github.com/allisonhorst/stats-illustrations)
]

- `snake_case_uses_underscores`
- `camelCaseUsesCaps`

Example:

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

---

## The workspace

```r
objects()
```

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

```r
rm(number)
objects()
```

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

---

# View prior code in history pane

# Use "up" arrow see previous code

---

# Staying organized

## 1) Save your code in .R files

> ### &zwj;File > New File > R Script

## 2) Keep work in R Project files

> ### File > New Project...

---

### 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.
]]

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

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

### - 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
```
]

```r
1 %% 2
```

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

```r
13 %% 2
```

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

Also works with negative numbers!

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

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

---

## Number "chopping" with 10s

```r
123456 %% 1
```

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

```r
123456 %% 10
```

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

```r
123456 %% 100
```

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

```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**

- 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**

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

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

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

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

```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**

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

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

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

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

---

## Other important points

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

```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)

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

### 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

```r
typeof(TRUE)
```

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

```r
typeof(FALSE)
```

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

```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
```

&zwj;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]

---

# <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="M504 256c0 136.997-111.043 248-248 248S8 392.997 8 256C8 119.083 119.043 8 256 8s248 111.083 248 248zm-248 50c-25.405 0-46 20.595-46 46s20.595 46 46 46 46-20.595 46-46-20.595-46-46-46zm-43.673-165.346l7.418 136c.347 6.364 5.609 11.346 11.982 11.346h48.546c6.373 0 11.635-4.982 11.982-11.346l7.418-136c.375-6.874-5.098-12.654-11.982-12.654h-63.383c-6.884 0-12.356 5.78-11.981 12.654z"/></svg> [HW 1](https://p4a.seas.gwu.edu/2022-Spring/hw1-getting-started.html) - read carefully!