Lab 1: R and RStudio

Author

YOUR NAME HERE

In this introductory lab, you will familiarize yourself with the R console and R Studio layout. Before you begin, you should install both R and RStudio using the instructions in the lecture slides. Follow the instructions below and submit a pdf document with your answers to the following questions on Gradescope.

Part A. Introduction to R

Open R (not RStudio). You should see a window that looks something like this (your version number may differ slightly):

At the bottom of this window, you should see a > symbol. This is called a prompt and indicates that R is waiting for instructions (in the form of code). Type 100 + 100 and then press return or enter. R should produce the following output: [1] 200. For now, ignore the [1]. This is R’s way of letting us know that the answer is a single value: 200.

Compute $2^{1023}$ by typing the line: 2 ^ 1023. What is the resulting value? Do you trust R’s answer?
Compute $2^{1024}$ by typing the line: 2 ^ 1024. What is the resulting value? Do you trust R’s answer?

We can save values as objects by giving them names. Try this out by typing x <- 10 and then pressing return/enter.

What does the command print(x) produce? Try to predict what the answer will be before you run the code.
What does the command x + 10 produce? Try to predict what the answer will be before you run the code.
Run the following two lines of code, one after the other. What is the result? Try to predict what the answer will be before you run the code.

x <- x + 1
x * x

Run the following lines of code, one after the other. What is the result? In your own words, explain what this code is doing.

sides <- c("H", "T")
flip1 <- sample(sides, 1, replace = T)
print(flip1)

Run the following lines of code, one after the other. What is the result? In your own words, explain what this code is doing.

sides <- c("H", "T")
flip10 <- sample(sides, 10, replace = T)
print(flip10)

Part B. Introduction to RStudio

Now, open RStudio. It should look some thing like this image, from the official RStudio Guide:

RStudio is like Microsoft Word/Google Docs for writing R code–it has useful tools (analogous to spell check) for programmers. In the lower left corner is your Console. This should look like the R window you were working in for Part A. The Console is meant for brief interactive R commands. The top right corner should be your Environment pane, which displays R objects that you have created. Right now your environment should be empty.

In the Console, type the command x <- 10. What do you see in your environment pane?
The bottom right pane is the Output pane, which will often be used to display results/visualizations of your R code. There are many tabs here, but click on the Files tab. What do you see? In your own words, explain what you think the Files tab shows.
Before this question, run the following line in the Console: install.packages("ggplot2"). This will install some additional R function for visualization. The top left pane is the Source pane. When you want to write more than one line of code at a time, it’s a good idea to organize your code in a single file. At the top of the RStudio window, click File -> New File -> R Script to open an untitled .R file. Copy and paste the following code into your R file. Then highlight the code and click Run (which will be in the top left corner of the Source pane). What do you see?

library(ggplot2)
mpg_plot <- ggplot(mpg, aes(x = displ, y = hwy)) + 
  geom_point(aes(color = class))
mpg_plot

When you are finished, remember to write up your solutions, save them in a pdf file, and submit to Gradescope.

--- title: "Lab 1: R and RStudio" author: "YOUR NAME HERE" format: html: embed-resources: true code-tools: true code-summary: "Code" --- In this introductory lab, you will familiarize yourself with the R console and R Studio layout. Before you begin, you should install both R and RStudio using the instructions in the lecture slides. **Follow the instructions below and submit a pdf document with your answers to the following questions on Gradescope.** ## Part A. Introduction to R Open R (not RStudio). You should see a window that looks something like this (your version number may differ slightly): ![](figures/console.png) At the bottom of this window, you should see a `>` symbol. This is called a prompt and indicates that R is waiting for instructions (in the form of code). Type `100 + 100` and then press return or enter. R should produce the following output: `[1] 200`. For now, ignore the `[1]`. This is R's way of letting us know that the answer is a **single** value: 200. 1. Compute $2^{1023}$ by typing the line: `2 ^ 1023`. What is the resulting value? Do you trust R's answer? 2. Compute $2^{1024}$ by typing the line: `2 ^ 1024`. What is the resulting value? Do you trust R's answer? We can save values as objects by giving them names. Try this out by typing `x <- 10` and then pressing return/enter. 3. What does the command `print(x)` produce? Try to predict what the answer will be before you run the code. 4. What does the command `x + 10` produce? Try to predict what the answer will be before you run the code. 5. Run the following two lines of code, one after the other. What is the result? Try to predict what the answer will be before you run the code. ```{r, eval = F} x <- x + 1 x * x ``` 6. Run the following lines of code, one after the other. What is the result? In your own words, explain what this code is doing. ```{r, eval = F} sides <- c("H", "T") flip1 <- sample(sides, 1, replace = T) print(flip1) ``` 7. Run the following lines of code, one after the other. What is the result? In your own words, explain what this code is doing. ```{r, eval = F} sides <- c("H", "T") flip10 <- sample(sides, 10, replace = T) print(flip10) ``` ## Part B. Introduction to RStudio Now, open RStudio. It should look some thing like this image, from the official [RStudio Guide](https://docs.posit.co/ide/user/ide/get-started/): ![](https://docs.posit.co/ide/user/ide/get-started/images/rstudio-panes-labeled.jpeg) RStudio is like Microsoft Word/Google Docs for writing R code--it has useful tools (analogous to spell check) for programmers. In the lower left corner is your Console. This should look like the R window you were working in for Part A. The Console is meant for brief **interactive** R commands. The top right corner should be your **Environment** pane, which displays R objects that you have created. Right now your environment should be empty. 8. In the **Console**, type the command `x <- 10`. What do you see in your environment pane? 9. The bottom right pane is the **Output** pane, which will often be used to display results/visualizations of your R code. There are many tabs here, but click on the **Files** tab. What do you see? In your own words, explain what you think the **Files** tab shows. 10. Before this question, run the following line in the **Console**: `install.packages("ggplot2")`. This will install some additional R function for visualization. The top left pane is the **Source** pane. When you want to write more than one line of code at a time, it's a good idea to organize your code in a single file. At the top of the RStudio window, click `File -> New File -> R Script` to open an untitled `.R` file. Copy and paste the following code into your R file. Then highlight the code and click `Run` (which will be in the top left corner of the Source pane). What do you see? ```{r, eval = F} library(ggplot2) mpg_plot <- ggplot(mpg, aes(x = displ, y = hwy)) + geom_point(aes(color = class)) mpg_plot ``` When you are finished, remember to write up your solutions, save them in a pdf file, and submit to Gradescope.