Assumptions & Ground Rules
(Note: This document was
created as an R Markdown file. You will learn about R Markdown files
later. First, I want to familiarize you with the RStudio
interface.)
The purpose of this first assignment is to demonstrate that you have
downloaded the “base R” and “RStudio” statistical programs and can open
a SPSS datafile in RStudio.
For all assignments in this class, you must have access to a computer
and should also use a cloud-based file system. (e.g. OneDrive,
Dropbox). Working from cloud
storage is essential - and not just for this class! By saving and
backing up using cloud storage, you will be able to access your saved
files from any computer, you will still have access to your saved files
if your computer were to unfortunately stop working, and you can easily
share files and folders with collaborators.
Thus, for this and all future assignments, I will assume you are
working on your own computer, are downloading base R and RStudio (free
open source) programs on your own computer, and are working from your
cloud storage via your computer’s file explorer.
Also, for this and all future assignments, you MUST type all commands
in by hand. Do not copy & paste except for troubleshooting purposes
(i.e., if you cannot figure out what you mistyped). Trust me - you will
learn better from typing.
- Early on, you may have a lot of trouble getting your code to run due
to minor typos. This is normal.
- Remember, you are learning to read and write a new (coding)
language. As with learning any new languages, we learn from practice -
and from correcting our mistakes.
Part 1 (Assignment 1.1)
Goal: Create new LastName_P680_work folder in your OneDrive cloud
storage, then download datasets and save to your new folder (i.e.,
“work” indicates this is the cloud folder within which you will do most
of your work for the course).
(Note: When following
instructions, always substitute “LastName” for your own last name! Also,
substitute YEAR_MO_DY for the actual date. E.g.,
Brauer_P680_Assign1_2021_08_23)
- On your computer, navigate to your OneDrive folder, then create a
new folder called “LastName_P680_work” in a location that is easy to
access (e.g., in the root OneDrive folder).
- Create two new folders in your P680_work folder: a “Datasets” folder
(LastName_P680_work > Datasets) and an “Assignments” folder
(LastName_P680_work > Datasets)
- Visit the Week 2 Module, below the “R Assignment 1: Introduction to
R & RStudio” entry, on the class Canvas site to download the SPSS
data file “MonitoringtheFuture2013grade10_0.sav.” This was downloaded
from the companion
website for Bachman & Paternoster’s Statistics for
Criminology & Criminal Justice, 4th Ed.
- Save the dataset in the new “LastName_P680_work > Datasets”
folder you made in Part 2.
- Open a Word document. At the top, put your name, date, course
information (F21-P680; Dr. Brauer), and heading (Assignment
1). Then, create a subheading for Part 1 (e.g., Assignment
1.1).
- Take a screenshot (#1) of your new
LastName_P680_work > Datasets folder with all six datasets downloaded
in it and past into a Word document.
- PC: ctrl + prt sc then ctrl + P into a Word document underneath the
subheading for Part 1. Or, in the search bar type in “snipping tool” and
use the tool to take a snapshot of your Datasets folder.
- Mac: Command + shift + 3, this saves on your desktop. Then, paste
into the Word document under the Part 1 subheading.
- Save the Word document with your screenshot to your
“LastName_P680_work > Assignments” folder. Name the file:
LastName_P680_Assign1_YEAR_MO_DY (e.g., I would name my
assignment: Brauer_P680_Assign1_2021_08_23).
Part 2 (Assignment 1.2)
Goal: Download R & RStudio; set Global Options; install “haven”
and “here” packages.
In this section, you will begin by downloading and installing two
programs on your computer: base R and RStudio.The first program, R, is
simultaneously a computer coding language and a statistical software
program. The second, RStudio, is an integrated development environment
(IDE) that provides a more user-friendly interface for working with the
R program. Throughout this course, you will learn to write and submit R
code in RStudio to run statistical commands in the R program. After
installing R & RStudio, you will run some simple commands to
familiarize yourself with the basic features of the program and install
two R packages.
- Follow the instructions at the link below to install the latest
versions of R and RStudio on your personal Windows or Mac computer:
- Visit Antoine Soetewey’s blog (AS blog) entry at the link
below, read the section titled “Main Components of RStudio,” and follow
along in RStudio on your computer:
- At the top of RStudio, navigate to “Tools” then click “Global
Options” and change the following settings:
- Uncheck “Restore .RData into workspace at startup”
- Change “Save workspace to .RData on exit” to “Never”
- Uncheck both boxes under “History”
- Our goal is to write and save standalone reproducible code
that can be run at any time by anyone with the file and associated file
structure. In my experience, these options aid in pursuit of that goal
while minimizing headaches when collaborating with others using shared
drives. For additional information, see Section
4.5 in Nicholas Tierney’s R Markdown for
Scientists. Because of this, unlike in the picture below, I
also remove the check from “Restore most recently opened project at
startup” and “Restore previously open source documents at startup.”
While I recommend doing so as well, you can decide whether or not it is
useful to you.
- Install “tidyverse” package
- (Note: We will use various
features of “tidyverse” in this class. For now, we are interested in the
“haven” package installed with tidyverse. The haven package allows us to
easily open the SPSS datafiles that you downloaded for Part 1 in
RStudio.)
- Open an “R Script” file (File > New File > R Script) if you
have not done so already (you should have if you followed along with the
AS blog).
- Type
install.packages("haven")
into the R Script,
select (i.e., highlight with cursor) this text line, and RUN the
selection (Windows: CTRL + Enter; Mac: cmd + Enter)
- The AS
blog referenced above gives brief directions on installing
packages and running R script selections. For more detailed instructions
on installing packages, see Danielle Navarro’s video
on the topic.
- Once installed, load the
haven
package by typing,
selecting, and running the command library("haven")
in your
R Script file.
- Now, repeat the process above to install the “here” package.
- Type
install.packages("here")
into your R Script file,
select (highlight) this text line, and RUN the selection (Windows: CTRL
+ Enter; Mac: cmd + Enter)
- Once installed, load the
here
package by typing,
selecting, and running library("here")
into your R Script
file.
- The
here
package will help you start a replicable
project-oriented workflow from the beginning. Here is how it will work
once installed:
- You save your primary R Script (or RMarkdown; we will learn about
these later) code file in your top-level directory folder. For us, that
means saving your R Script file in your LastName_P680_work folder.
- Next, after closing RStudio, you will simply click directly on the R
Script file in your LastName_P680_work folder to automatically open it
with RStudio. When you do this, your “working directory,” i.e., the
place R looks for files by default, will automatically be set to your
P680_work folder.
- The
here
package will then make it easy to find and
call objects (e.g., SPSS dataset) in subfolders of your working
directory (e.g., in “Datasets” folder).
- Check to see if the
haven
and here
packages loaded properly.
- First, find the “Packages” tab (see “blue pane” in AS
blog).
- Next, scroll down through the listed packages until you find the
haven and here package entries.
- If there are checkmarks next to both entries, it worked!
- While you are at it, repeat the process above to install the
tidyverse
package.
- Take a screenshot (#2) of RStudio session, then
paste it under a new Part 2 (Assignment 1.2) subheading in the “Assign1”
Word document you created and saved earlier (in your “Assignments”
folder).
Part 3 (Assignment 1.3)
Goal: Save R Script; use haven package to open SPSS file in
RStudio
- In RStudio, click File > Save As, then save R Script file in
LastName_P680_work folder. Name the file:
LastName_P680_Assign1_RScript_YEAR_MO_DY
- It is essential that your R Script files (and, later, R
Markdown files) are saved in the top-level LastName_P680_work folder for
the
here
package to work properly.
- As in the picture above, your R Script should be in the same P680
folder as the “Datasets” and “Assignments” folders.
- After saving your R Script file, close RStudio, then reopen directly
from R Script.
- Open P680_work folder, locate new R Script file
(LastName_P680_Assign1_RScript_YEAR_MO_DY), and click or double-click to
open with RStudio.
- By opening RStudio directly from the R Script file saved in your
P680_work folder, the
here
package by default will set the
P680_work folder as the top-level working directory
- Add
#comments
to R code and load haven
and
here
packages
- In your R Script, place hashmarks (#) in front of both
install.packages
commands.
- The
haven
and here
packages should already
be installed, so you should not need to run these lines again.
- Placing a hashmark in front of a command – or in front of any text
in R code – will create a “comment” that will not be run as a command in
R.
- After commenting out the
#install.packages
commands,
run both library
commands to load the haven
and here
packages.
- Though already installed, you will need to reload all packages that
you want to use at the beginning of each R session.
- Tip: Since you want to run all commands in your R Script
that are not commented out (i.e., both
library
commands),
try running the entire script instead of only a selection.
- Check the “Packages” tab to make sure there are checkmarks by the
“haven” and “here” packages.
- Your R Script should now look similar to this:
- Note the red text in the Console that appeared after loading the
here package. It confirms the here package has set my LastName_P680_work
folder (i.e., for me, P680_work_Brauer) as the top-level working
directory.
- Open SPSS dataset in RStudio using haven package and save data as an
object in R
- Type the following command in your R Script file:
read_spss(here(“Datasets”,’MonitoringtheFuture2013grade10_0.sav’))
read_spss()
is a haven package command that allows R to
read SPSS datafiles
- Inside the
read_spss()
parentheses, we need to specify
the file location and the filename we wish to open, separated by a
comma.
- Instead of specifying the exact path location, we specify
here(“Datasets”,
which uses the here package to locate our
“Datasets” folder. By using the here package, your R code should work
for anyone on any computer as long as they have the exact same file
structure (e.g., you can work from local or cloud storage, or work from
different computers)
- Next, our code specifies the
’MonitoringtheFuture2013grade10_0.sav’
file in the
“Datasets” folder to open.
- Run the
read_spss
command. You should see a small
snapshot of the data in your R console, which looks something like this:
- You just read a dataset into RStudio!
- However, you do not want the dataset in the R Console – you want to
be able to call the dataset as an object on which you can do things,
such as summarize or correlate variables (later). To do this, you need
to save the dataset into the R Environment. (Note that your R
Environment tab is still empty.)
- To save the dataset as an object in R, type
MF2013g10data <-
before the
read_spss()
command.
- The text
MF2013g10data
is the name we are giving to the
data object we are creating.
- The
<-
command tells R to place whatever follows the
text arrow (in this case, the dataset read by the read_spss
command) into our MF2013g10data
object.
- ****Note:*** We can name the object whatever we want (e.g.,
mydata
). However, it is good coding practice to be
systematic in creating concise yet informative names. The name I
selected reminds me that the object is the
Monitoring the Future
2013 grade 10
data.
- Also, R code is case-specific, so be careful and consistent with
using upper- and lower-case letters!
- By this point, you may be wondering why I care so much about how you
name your folders and files. The short answer is that thoughtful and
systematic naming conventions can save you a lot of time and can be very
helpful to your future self or to others attempting to reproduce your
work. In contrast, ad hoc names can cause a great deal of
unnecessary frustration. I recommend Danielle Navarro’s videos on Names
machies like and Names
humans like for more information and useful file naming tips.
- Your R Script code should look like this:
- Run the line of code in your R Script to create the new data
object.
- Take a screenshot (#3) of RStudio session. Paste
into your “Assign1” Word document (saved in “Assignments” folder) under
a new Part 3 (Assignment 1.3) subheading.
Part 4
Goal: Submitting your first assignment
- After completing the first four parts of this assignment, you should
have one “Assign1” Word document in your “Assignments” folder that
contains all three (3) of your screenshots. Additionally, you should
have an “Assign1_RScript” file in your LastName_P680_work folder.
- Previously, I sent you an invite to a shared OneDrive folder
(“Brauer-F21-P680”). Navigate to our shared folder. Inside this shared
folder, create a new folder named:
LastName_P680_commit. The “commit” part indicates that
you are ready to commit to sharing whatever you place in this folder.
When collaborating with others, it is good practice to keep separate
“work” and “commit” folders and then only to place a file or folder in
your collaborative “commit” folder when is done and ready to be viewed
(or, in this case, graded) by others.
- Inside the “LastName_P680_commit” folder in our shared folder,
create another folder named: Assignment 1.
- To submit your assignment for grading, save copies of both your (1)
“Assign1” Word file and (2) your “Assign1_RScript file” into the
LastName_P680_commit > Assignment 1 folder. Be sure to save
copies of both files - do not just drag the files over from
your “work” folder, or you may lose those original copies from your
“work” folder.