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SOLVED CSE 6242 / CX 4242 HW 2: Tableau, D3 Graphs, and Visualization
Q1 [25 points] Designing a good table. Visualizing data with Tableau.
Goal Design a table, a grouped bar chart, and a stacked bar chart with filters in Tableau.
Technology Tableau Desktop
Deliverables Gradescope: After selecting HW2 - Q1, click Submit Images. You will be taken to a
list of questions for your assignment. Click Select Images and submit the following
four PNG images under the corresponding questions:
● table.png: Image/screenshot of the table in Q1.1
● grouped_barchart.png: Image of the chart in Q1.2
● stacked_barchart_1.png: Image of the chart in Q1.3 after filtering data for
Max.Players = 2
● stacked_barchart_2.png: Image of the chart in Q1.3 after filtering data for
Max.Players = 4 a
Q1 will be manually graded after the grace period.
Setting Up Tableau
Install and activate Tableau Desktop by following “HW2 Instructions” on Canvas. The product activation key
is for your use in this course only. Do not share the key with anyone. If you already have Tableau Desktop
installed on your machine, you may use this key to reactivate it.
a
If you do not have access to a Mac or Windows machine, use the 14-day trial version of Tableau Online:
1. Visit https://www.tableau.com/trial/tableau-online
2. Enter your information (name, email, GT details, etc.)
3. You will then receive an email to access your Tableau Online site
4. Go to your site and create a workbook a
If neither of the above methods work, use Tableau for Students. Follow the link and select "Get Tableau For
Free". You should be able to receive an activation key which offers you a one-year use of Tableau Desktop
at no cost by providing a valid Georgia Tech email.
Connecting to Data
1. It is optional to use Tableau for Q1.1. Otherwise, complete all parts using a single Tableau workbook.
2. Q1 will require connecting Tableau to two different data sources. You can connect to multiple data sources
within one workbook by following the directions here.
3. For Q1.1 and Q1.2:
a. Open Tableau and connect to a data source. Choose To a File – Text file. Select the
popular_board_game.csv file from the skeleton.
b. Click on the graph area at the bottom section next to "Data Source" to create worksheets.
4. For Q1.3:
a. You will need a data.world account to access the data for Q1.3. Add a new data source by
clicking on Data – New Data Source.
b. When connecting to a data source, choose To a Server – Web Data Connector.
c. Enter this URL to connect to the data.world data set on board games. You may be prompted to
log in to data-world and authorize Tableau. If you haven’t used data.world before, you will be
required to create an account by clicking “Join Now”. Do not edit the provided SQL query.
a
NOTE: If you cannot connect to data-world, you can use the provided csv files for Q1 in the skeleton. The
provided csv files are identical to those hosted online and can be loaded directly into Tableau. a
d. Click the graph area at the bottom section to create another worksheet, and Tableau will
automatically create a data extract.
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Table and Chart Design
1. [5 points] Good table design. Visualize the data contained in popular_board_game.csv as a data table
(known as a text table in Tableau). In this part (Q1.1), you can use any tool (e.g., Excel, HTML, Pandas,
Tableau) to create the table.
We are interested in grouping popular games into "support solo" (min player = 1) and
"not support solo" (min player > 1). Your table should clearly communicate information about these two groups
simultaneously. For each group (Solo Supported, Solo Not Supported), show: a
a. Total number of games in each category (fighting, economic, ...)
b. In each category, the game with the highest number of ratings. If more than one game has the same
(highest) number of ratings, pick the game you prefer. NOTE: Level of Detail expressions may be useful if
you use Tableau.
c. Average rating of games in each category (use simple average), rounded to 2 decimal places.
d. Average playtime of games in each category, rounded to 2 decimal places.
e. In the bottom left corner below your table, include your GT username (In Tableau, this can be done
by including a caption when exporting an image of a worksheet or by adding a text box to a dashboard.
If you use Tableau, refer to the tutorial here).
f. Save the table as table.png. (If you use Tableau, go to Worksheet/Dashboard Export Image).
NOTE: Do not take screenshots in Tableau since your image must have high resolution. You can take a
screenshot If you use HTML, Pandas, etc. a
Your learning goal here is to practice good table design, which is not strongly dependent on the tool that you
use. Thus, we do not require that you use Tableau in this part. You may decide the most meaningful column
names, the number of columns, and the column order. You are not limited to only the techniques described
in the lecture. For OMS students, the lecture video on this topic is Week 4 - Fixing Common Visualization
Issues - Fixing Bar Charts, Line Charts. For campus students, review lecture slides 42 and 43.
2. [10 points] Grouped bar chart. Visualize popular_board_game.csv as a grouped bar chart in Tableau.
Your chart should display game category (e.g., fighting, economic,...) along the horizontal axis and game
count along the vertical axis. Show game playtime (e.g., <=30, (30, 60]) for each category. NOTE: Do not
differentiate between “support solo” and “non-support solo” for this question. a. a
a. Design a vertically grouped bar chart. For each category, show the game count for each playtime.
b. Include clearly labeled axes, a clear chart title, and a legend.
c. In the bottom left corner of your image, include your GT username.NOTE: In Tableau, this can be done
by including a caption when exporting an image of a worksheet or by adding a text box to a dashboard.
Refer to the tutorial here.
d. Save the chart as grouped_barchart.png (go to Worksheet/Dashboard Export Image.
a. NOTE: Do not take screenshots in Tableau since your image must have high resolution.
The main goal here is for you to get familiarized with Tableau. Thus, we kept this open-ended, so you can
practice making design decisions. We will accept most designs. We show one possible design in Figure
1.2, based on the tutorial from Tableau.
3. [10 points] Stacked bar chart. Visualize the data.world dataset (or games_detailed_info_filtered.csv if
using the local files in the skeleton) as a stacked bar chart. Showcase the count of games in different
categories and the relationship between game categories, their mechanics, and max player size. a
a. Create a Worksheet with a stacked bar chart that shows game counts for each playing mechanic
(sub-bars) for each game category. NOTE: This data contains duplicate rows, as each row represents
a distinct game. Do not remove duplicate rows from the data.
b. Display game counts along the vertical axis and category along the horizontal axis.
c. Include clear axes labels, a clear chart title, and a legend.
d. Create a Dashboard using the worksheet you created.
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e. Add a filter for the number of 'Max.Players' allowed in each game. Update the chart using this filter to
generate the following chart images (Refer to the tutorial here on how to add a filter in a dashboard.
Make sure to add 'Max.Players' in the filter shelf in the Worksheet first, like this):
i. Select "2 Players" only in the filter. Save the resulting chart as 'stacked_barchart_1.png'
ii. Select "4 Players" only in the filter. Save the resulting chart as 'stacked_barchart_2.png'
iii. Both images must include your GT username in the bottom left. This can be added using a
text box. Refer to the tutorial here.https://youtu.be/fRwQenvBJ6I
iv. In each image, the filter must be visible. If you are using Tableau Online, you may need to
add your worksheet containing the chart to a dashboard and then download an image of the
dashboard that contains both the filter and the chart.
Note: To save a dashboard image, go to Dashboard - Export Image. Do not submit screenshots. An example of a
possible design is shown in Figure 1.3.
Optional Reading: The effectiveness of stacked bar charts is often debated—sometimes, they can be confusing, difficult
to understand, and may make data series comparisons challenging.
Figure 1.2: Example of a grouped bar chart. Your chart may appear different and can earn full credit if it meets all the
stated requirements. Your submitted image should include your GT username in the bottom left.
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Figure 1.3: Example of a stacked bar chart after selecting "4 Players" in Max.Players filter. Your chart may appear
different and can earn full credit if it meets all the stated requirements. Your submitted image should include your GT
username in the bottom left.
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Important Points about Developing with D3 in Questions 2–5
1. We highly recommend that you use the latest Chrome browser to complete this question. We will
grade your work using Chrome v92 (or higher).
2. You will work with version 5 of D3 in this homework. You must NOT use any D3 libraries (d3*.js) other
than the ones provided in the lib folder.
3. For Q3–5, your D3 visualization MUST produce a DOM structure as specified at the end of each
question. Not only does the structure help guide your D3 code design, but it also enables your code
to be auto-graded (the auto-grader identifies and evaluates relevant elements in the rendered HTML).
We highly recommend you review the specified DOM structure before starting to code.
4. You need to setup a local HTTP server in the root (hw2-skeleton) folder to run your D3
visualizations, as discussed in the D3 lecture (OMS students: the video "Week 5 - Data Visualization
for the Web (D3) - Prerequisites: JavaScript and SVG". Campus students: see lecture PDF.). The
easiest way is to use http.server for Python 3.x. (for more details, see link).
5. All d3*.js files in the lib folder must be referenced using relative paths, e.g., "../lib/"
in your html files. For example, if the file "Q2/submission.html" uses d3, its header should contain:
It is incorrect to use an absolute path such as:
6. For questions that require reading from a dataset, use a relative path to read in the dataset file. For
example, suppose a question reads data from earthquake.csv, the path should simply be
"earthquake.csv" and NOT an absolute path such as "C:/Users/polo/hw2-skeleton/Q/earthquake.csv".
7. You can and are encouraged to decouple the style, functionality and markup in the code for each
question. That is, you can use separate files for CSS, JavaScript and html.
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Q2 [15 points] Force-directed graph layout
Goal Create a network graph shows relationships between games in D3. Use interactive
features like pinning nodes to give the viewer some control over the visualization.
Technology D3 Version 5 (included in the lib folder)
Chrome v92.0 (or higher): the browser for grading your code
Python http server (for local testing)
Allowed Libraries D3 library is provided to you in the lib folder. You must NOT use any D3 libraries
(d3*.js) other than the ones provided. On Gradescope, these libraries are provided
for you in the auto-grading environment.
Deliverables [Gradescope] Q2.(html/js/css): The HTML, JavaScript, CSS to render the
graph. Do not include the D3 libraries or board_games.csv dataset.
You will experiment with many aspects of D3 for graph visualization. To help you get started, we have
provided the Q2.html file (in the Q2 folder) and an undirected graph dataset of boardgames, board_games.csv
file (in the Q2 folder). The dataset for this question was inspired by a Reddit post about visualizing
boardgames as a network, where the author calculates the similarity between board games based on
categories and game mechanics where the edge value between each board game (node) is the total weighted
similarity index. This dataset has been modified and simplified for this question and does not fully represent
actual data found from the post. The provided Q2.html file will display a graph (network) in a web browser.
The goal of this question is for you to experiment with the visual styling of this graph to make a more
meaningful representation of the data. Here is a helpful resource (about graph layout) for this question.
Note: You can submit a single Q2.html that contains all the css and js components; or you can split Q2.html
into Q2.html, Q2.css, and Q2.js.
1. [2 points] Adding node labels: Modify Q2.html to show the node label (the node name, e.g., the source)
at the top right of each node in bold. If a node is dragged, its label must move with it.
2. [3 points] Styling edges: Style the edges based on the "value" field in the links array:
1. If the value of the edge is equal to 0 (similar), the edge should be gray, thick, and solid (The dashed
line with zero gap is not considered as solid).
2. If the value of the edge is equal to 1 (not similar), the edge should be green, thin, and dashed.
3. [3 points] Scaling nodes:
a. [1.5 points] Scale the radius of each node in the graph based on the degree of the node (you may try
linear or squared scale, but you are not limited to these choices).
Note: Regardless of which scale you decide to use, you should avoid extreme node sizes, which will
likely lead to low-quality visualization (e.g., nodes that are mere points, barely visible, or of huge sizes
with overlaps).
Note: D3 v5 does not support d.weight (which was the typical approach to obtain node degree in D3
v3). You may need to calculate node degrees yourself. Example relevant approach is here.
b. [1.5 points] The degree of each node should be represented by varying colors. Pick a meaningful
color scheme (hint: color gradients). There should be at least 3 color gradations and it must be visually
evident that the nodes with a higher degree use darker/deeper colors and the nodes with lower
degrees use lighter colors. You can find example color gradients at Color Brewer.
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4. [6 points] Pinning nodes:
a. [2 points] Modify the code so that dragging a node will fix (i.e., "pin") the node's position such that it
will not be modified by the graph layout algorithm (Note: pinned nodes can be further dragged around
by the user. Additionally, pinning a node should not affect the free movement of the other nodes).
Node pinning is an effective interaction technique to help users spatially organize nodes during graph
exploration. The D3 API for pinning nodes has evolved over time. We recommend reading this post
when you work on this sub-question.
b. [1 points] Mark pinned nodes to visually distinguish them from unpinned nodes, i.e., show pinned
nodes in a different color.
c. [3 points] Double clicking a pinned node should unpin (unfreeze) its position and unmark it. When a
node is no longer pinned, it should move freely again.
IMPORTANT:
1. To pass autograder consistently for part 1 (which tests if a dragged node becomes pinned and retains
its position), you may need to increase the radius of highly weighted nodes and reduce their label
sizes, so that the nodes can be more easily detected by the autograder's webdriver mouse cursor.
2. To avoid timeout errors on Gradescope, complete the double click function in part 3 before submitting.
3. If you receive timeout messages for all parts and your code works locally on your computer, verify that
you are indeed using the appropriate ids provided in the "add the nodes" section in the skeleton code.
4. D3 v5 does not support the d.fixed method (it was deprecated after D3 v3). For our purposes, it is
used as a Boolean value to indicate whether a node has been pinned or not.
5. [1 points] Add GT username: Add your Georgia Tech username (usually includes a mix of letters and
numbers, e.g., gburdell3) to the top right corner of the force-directed graph (see example image). The GT
username must be a element having the id: "credit"
Figure 2: Example of Visualization with pinned node (yellow). Your chart may appear different and can earn
full credit if it meets all the stated requirements.
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Q3 [15 points] Line Charts
Goal Explore temporal patterns in the BoardGameGeek data using line charts in D3 to
compare how the number of ratings grew. Integrate additional data about board
game rankings onto these line charts and explore the effect of axis scale choice.
Technology D3 Version 5 (included in the lib folder)
Chrome v92.0 (or higher): The browser used for grading your code
Python HTTP server (for local testing)
Allowed Libraries D3 library is provided to you in the lib folder. You must NOT use any D3 libraries
(d3*.js) other than the ones provided. On Gradescope, these libraries are provided
for you in the autograder environment.
Deliverables [Gradescope] Q3.(html / js / css): The HTML, JavaScript, CSS to render the line
charts. Do not include the D3 libraries or boardgame_ratings.csv dataset.
Use the dataset in the file boardgame_ratings.csv (in the Q3 folder) to create line charts. Refer to the tutorial
for line chart here:
Note: You will create four charts in this question, which should be placed one after the other on a single
HTML page, like the example image below (Figure 3). Note that your design need NOT be identical to the
example; however, the submission must follow the DOM structure specified at the end of this question.
IMPORTANT: use the Margin Convention guide for specifying chart dimensions and layout. The autograder
will assume this convention has been followed for grading purposes. The SVG viewBox attribute is not
recommended to define the position and dimension of your SVG.
1. [5 points] Creating line chart. Create a line chart (Figure 3.1) that visualizes the number of board game
ratings from November 2016 to August 2020 (inclusively), for the eight board games: ['Catan', 'Dominion',
'Codenames', 'Terraforming Mars', 'Gloomhaven', 'Magic: The Gathering', 'Dixit', 'Monopoly']. Use
d3.schemeCategory10() to differentiate these board games. Add each board game's name next to its
corresponding line. For the x-axis, show a tick label for every three months. Use D3 axis.tickFormat() and
d3.timeFormat() to format the ticks to display abbreviated months and years. For example, Jan 17, Apr
17, Jul 17. (See Figure 3.1 and its x-axis ticks).
● Chart title: Number of Ratings 2016-2020
● Horizontal axis label: Month. Use D3.scaleTime().
● Vertical axis label: Num of Ratings. Use a linear scale (for this part).
VERY IMPORTANT — Beware of “Silent Date Conversion": Opening the csv file in an application like
Excel may silently modify date strings without warning you, e.g., converting hyphen-separated date strings
(e.g., 2016-11-01) into slash-separated date strings (e.g., 11/01/16). Impacted students would see a
“correct” line chart visualization on their local computers, but when they upload their code to Gradescope,
test cases will fail (e.g., tick labels are not found, lines are not drawn) because the x-scale cannot be
computed (as the dates are parsed as NaN). To view the content of a csv file, we recommend you
only use text editors (e.g., sublime text, notepad) that do not silently modify csv files.
2. [5 points] Adding board game rankings. Create a line chart (Figure 3.2) for this part (append to the
same HTML page) whose design is a variant of what you have created in part 1. Start with your chart from
part 1. Modify the code to visualize how the rankings of ['Catan', 'Codenames', 'Terraforming Mars',
'Gloomhaven'] change over time by adding a symbol with the ranking text on their corresponding lines.
Show the symbol for every three months and exactly align with the x-axis ticks in part 1. (See Figure 3.2).
Add a legend to explain what this symbol represents next to your chart (See the Figure 3.2 bottom right).
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● Chart title: Number of Ratings 2016-2020 with Rankings
3. [5 points] Axis scales in D3. Create two line charts (Figure 3.3-1 and 3.3-2) for this part (append to the
same HTML page) to try out two axis scales in D3. Start with your chart from part 2. Then modify the
vertical axis scale for each chart: the first chart uses the square root scale for its vertical axis (only), and
the second chart uses the log scale for its vertical axis (only). Keep the symbols and the symbol legend
you implemented in part 2. At the bottom right of the last chart, add your GT username (e.g., gburdell3,
see Figure 3.3-2 for example).
Note: the horizontal axes should be kept in linear scale, and only the vertical axes are affected.
Hint: You may need to carefully set the scale domain to handle the 0s in data.
● First chart (Figure 3.3-1)
○ Chart title: Number of Ratings 2016-2020 (Square root Scale)
○ This chart uses the square root scale for its vertical axis (only)
○ Other features should be the same as part 2.
● Second chart (Figure 3.3-2)
○ Chart title: Number of Ratings 2016-2020 (Log Scale)
○ This chart uses the log scale for its vertical axis (only). Set the y-scale domain minimum to 1.
○ Other features should be the same as part 2.
Figure 3.1: Example line chart. Your chart may appear different and can earn full credit if it meets all stated
requirements.
Figure 3.2: Example of a line chart with rankings. Your chart may appear different and can earn full credit if it meets all
stated requirements.
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Figure 3.3-1: Example of a line chart using square root scale. Your chart may appear different and can earn full credit
if it meets all stated requirements.
Figure 3.3-2: Example of a line chart using log scale. Your chart may appear different and can earn full credit if it
meets all stated requirements.
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Note: Your D3 visualization MUST produce the following DOM structure.
containing GT username
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Q4 [20 points] Interactive Visualization
Goal Create line charts in D3 that use interactive elements to display additional data. Then
implement a bar chart that appears when you mouse over a point on the line chart.
Technology D3 Version 5 (included in the lib folder)
Chrome v92.0 (or higher): the browser for grading your code
Python http server (for local testing)
Allowed Libraries D3 library is provided to you in the lib folder. You must NOT use any D3 libraries
(d3*.js) other than the ones provided. On Gradescope, these libraries are provided
for you in the auto-grading environment.
Deliverables [Gradescope] Q4.(html/js/css): The HTML, JavaScript, CSS to render the
visualization in Q4. Do not include the D3 libraries or average-rating.csv dataset.
Use the dataset average-rating.csv provided in the Q4 folder to create an interactive frequency polygon
line chart. This dataset contains a list of games, their ratings and supporting information like the numbers of
users who rated a game and the year a game was published. In the data sample below, each row under the
header represents a game name, year of publication, average rating, and the number of users who rated the
game. Helpful resource to work with nested data in D3: https://gist.github.com/phoebebright/3176159
name,year,average_rating,users_rated
Codenames,2015,7.71148,51209
King of Tokyo,2011,7.23048,48611
1. [3 points] Create a line chart. Summarize the data by displaying the count of board games by rating for
each year. Round each rating down to the nearest integer, using Math.floor(). For example, a rating of
7.71148 becomes 7. For each year, sum the count of board games by rating. Display one plot line for
each of the 5 years (2015-2019) in the dataset. Note: the dataset comprises year data from 2011 to 2020;
this question asks to plot lines for the years 2015-2019. If some of the datapoints in the chart do not have
ratings, generate dummy values (0s) to be displayed on the chart for the required years.
All axes must start at 0, and their upper limits must be automatically adjusted based on the data. Do not
hard-code the upper limits. Note: if you are losing points on Gradescope for axis or scale, ensure that
you are using the proper margin convention without any additional paddings or translations.
• The vertical axis represents the count of board games for a given rating. Use a linear scale.
• The horizontal axis represents the ratings. Use a linear scale.
2. [3 points] Line styling, legend, title and username.
• For each line, use a different color of your choosing. Display a filled circle for each rating-count
data point.
• Display a legend on the right-hand portion of the chart to show how line colors map to years.
• Display the title "Board games by Rating 2015-2019" at the top of the chart.
• Add your GT username (usually includes a mix of lowercase letters and numbers, e.g., gburdell3)
beneath the title (see example Figure 4.1).
Figure 4.1 shows an example line chart design. Yours may look different but can earn full credit if it meets all
stated requirements.
Note: The data provided in average-rating.csv requires some processing for aggregation. All
aggregation must only be performed in JavaScript; you must NOT modify average-rating.csv.
That is, your code should first read the data from .csv file as is, then you may process the loaded data using
JavaScript. If you are getting a MoveTargetOutOfBoundsException, (a) check that your margin convention
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is correct, and (b) make sure to check the Dropbox linked screenshot of your graph to get a good idea of
how the plot could be Improved compared to the sample graph provided.
Figure 4.1: Line chart representing count of board games
by rating for each year. Your chart may appear different but
can earn full credit if it meets all stated requirements.
Figure 4.2: Bar chart representing the number of
users who rated the top 5 board games with the rating
6 in year 2019. Your chart may appear different but
can earn full credit if it meets all stated requirements.
Interactivity and sub-chart. In the next few sub-questions, you will create event handlers to detect
mouseover and mouseout events over each circle that you added in Q4.2.
3. [8 points] Create a horizontal bar chart, so that when hovering over a circle, that bar chart will be shown
below the line chart. The bar chart displays the top 5 board games that received the highest numbers of
user ratings (users_rated), for the hovered year and rating. For example, hovering over the rating-6
circle for 2019 will display the bar chart for the number of users who rated the top 5 board games. If a
certain year/rating combination has fewer than 5 entries, it should display as many as there are. Figure
4.2 shows an example design. Show one bar per game. The bar length represents the number of users
who rated the game.
Note: No bar chart should be displayed when the count of games is 0 for hovered year and rating.
Axes: All axes should be automatically adjusted based on the data. Do not hard-code any values.
• The vertical axis represents the board games. Sort the game names in descending order, such that
the game with the highest users_rated is at the bottom, and the game with the smallest users_rated
is at the top. Some boardgame names are quite long. For each game name, display its first 10
characters (if a name has fewer than 10 characters, display them all). A space counts as a character.
The horizontal axis represents the number of users who rated the game (for the hovered year and
rating). Use a linear scale.
• Set horizontal axis label to 'Number of users' and vertical axis label to 'Games'.
4. [2 points] Bar styling, grid lines and title
• Bars: All bars should have the same color regardless of year or rating. All bars for the specific year
should have a uniform bar thickness.
• Grid lines should be displayed.
• Title: Display a title with the format "Top 5 Most Rated Games of with Rating " at the
top of the chart where and are what the user hovers over in the line chart. For
example, hovering over rating 6 in 2015, the title would read: "Top 5 Most Rated Games of 2015 with
Rating 6"
5. [2 points] Mouseover Event Handling
• The bar chart and its title should only be displayed during mouseover events for a circle in the line
chart.
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• The circle in the line chart should change to a larger size during mouseover to emphasize that it is the
selected point.
• When count of games is 0 for hovered year and rating, no bar chart should be displayed. The hoveredover circle on the line graph should still change to a larger size to show it is selected.
Hint: .attr() is generally used for describing the size, shape, location, etc. of an element, whereas .style() is
used for other design aspects like color, opacity, etc.
6. [2 points] Mouseout Event Handling
The bar chart and its title should be hidden from view on mouseout and the circle previously mouseover-ed
should return to its original size in the line chart.
The graph should exhibit interactivity similar to Figure 4.6 where the mouse is over the larger circle.
Figure 4.6: Line chart and bar chart demonstrating interactivity. Your chart may appear different, but you can earn full
credit if it meets all stated requirements.
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Note: Your D3 visualization MUST produce the following DOM structure.