Bar charts (horizontal and vertical) in Tableau - Cell-by-Cell Formula Trace

Concept Flow

Category    Sales
Books      150
Clothing   200
Electronics 300
Furniture  100

Step 1: Group by Category
Step 2: Sum Sales per Category
Step 3: Plot bars with Category and Sales

We start with sales data by category. We group the data by category, sum the sales for each group, then plot bars where each bar length shows total sales for that category.

Formula

SUM([Sales]) by [Category]

This Tableau formula groups sales data by category and sums the sales values for each category to prepare data for bar chart plotting.

Step-by-Step Trace

Category	Sales
Books	150
Clothing	200
Electronics	300
Furniture	100

The table shows total sales per category after grouping and summing.

Variable Tracker

Variable	Value	Explanation
Category Groups	Books, Clothing, Electronics, Furniture	Categories identified for grouping
Sales Sum per Category	150, 200, 300, 100	Sum of sales values for each category
Bar Lengths	150, 200, 300, 100	Bar lengths correspond to summed sales

Key Moments

What does grouping by Category achieve?

How is the sales sum calculated?

What does the bar length represent in the chart?

Sheet Trace Quiz - 3 Questions

Which step shows the total sales for Electronics?

A Step 1: Group data by Category

B Step 3: Plot bars with Category on axis

C Step 2: Calculate sum of Sales for each Category

D None of the above

Key Result

Bar charts visualize grouped and summed data by showing bars whose lengths represent values like sales totals per category.

Transcript

We start with sales data by category. First, we group the data by category names. Then, we sum the sales values within each group. Finally, we plot bars where each bar's length shows the total sales for that category. This can be done vertically or horizontally in Tableau by placing Category on one axis and the summed Sales on the other. The longer the bar, the higher the sales amount. This simple visual helps compare categories easily.

Practice

1. Which of the following best describes a vertical bar chart in Tableau?

easy

A. Dimension on Columns and Measure on Rows

B. Dimension on Rows and Measure on Columns

C. Both Dimension and Measure on Rows

D. Both Dimension and Measure on Columns

Solution

1. Step 1: Understand vertical bar chart layout

   Vertical bars are created by placing the dimension on Columns and the measure on Rows in Tableau.

2. Step 2: Match the layout to options

   Dimension on Columns and Measure on Rows matches this layout exactly.

3. Final Answer:

   Dimension on Columns and Measure on Rows -> Option A

4. Quick Check:

   Vertical bars = Dimension on Columns, Measure on Rows [OK]

Hint: Vertical bars: dimension columns, measure rows [OK]

Common Mistakes:

• Confusing horizontal and vertical bar chart layouts
• Placing both dimension and measure on the same shelf
• Swapping rows and columns incorrectly

2. Which Tableau shelf placement creates a horizontal bar chart?

easy

A. Dimension on Rows, Measure on Columns

B. Dimension on Columns, Measure on Rows

C. Measure on Rows only

D. Dimension on Rows only

Solution

1. Step 1: Recall horizontal bar chart setup

   Horizontal bars are made by placing the dimension on Rows and the measure on Columns.

2. Step 2: Identify correct option

   Dimension on Rows, Measure on Columns matches this setup exactly.

3. Final Answer:

   Dimension on Rows, Measure on Columns -> Option A

4. Quick Check:

   Horizontal bars = Dimension on Rows, Measure on Columns [OK]

Hint: Horizontal bars: dimension rows, measure columns [OK]

Common Mistakes:

• Mixing up rows and columns shelves
• Placing only measures without dimensions
• Choosing options with missing shelves

3. Given a dataset with 'Category' as dimension and 'Sales' as measure, what will be the result of placing 'Category' on Rows and 'Sales' on Columns in Tableau?

medium

A. A scatter plot comparing categories and sales

B. A horizontal bar chart showing sales per category

C. A line chart showing sales trend

D. A vertical bar chart showing sales per category

Solution

1. Step 1: Analyze shelf placement

   Category on Rows and Sales on Columns creates vertical bars representing sales per category.

2. Step 2: Identify chart type

   This layout produces a vertical bar chart, not horizontal or other chart types.

3. Final Answer:

   A vertical bar chart showing sales per category -> Option D

4. Quick Check:

   Category rows + Sales columns = vertical bars [OK]

Hint: Category rows + Sales columns = vertical bar chart [OK]

Common Mistakes:

• Assuming horizontal bars instead of vertical
• Confusing bar chart with line or scatter plot
• Ignoring shelf placement rules

4. You created a bar chart but the bars are vertical when you wanted horizontal bars. What is the most likely fix?

medium

A. Remove the dimension from the view

B. Change the mark type to Line

C. Swap the dimension and measure between Rows and Columns shelves

D. Add a filter to the data

Solution

1. Step 1: Identify cause of vertical bars

   Vertical bars appear when dimension is on Rows and measure on Columns.

2. Step 2: Fix by swapping shelves

   To get horizontal bars, swap dimension to Columns and measure to Rows.

3. Final Answer:

   Swap the dimension and measure between Rows and Columns shelves -> Option C

4. Quick Check:

   Swap shelves to switch bar orientation [OK]

Hint: Swap dimension and measure shelves to change bar direction [OK]

Common Mistakes:

• Changing mark type instead of shelf placement
• Removing dimension causing no bars
• Adding filters unrelated to orientation

5. You want to create a dashboard showing sales by region with horizontal bars, but also want to add a vertical bar chart showing profit by region side by side. How should you set up the shelves for each chart in Tableau?

hard

A. For sales: Dimension on Columns, Measure on Rows; For profit: Dimension on Rows, Measure on Columns

B. For sales: Dimension on Rows, Measure on Columns; For profit: Dimension on Columns, Measure on Rows

C. For sales: Dimension on Columns, Measure on Columns; For profit: Dimension on Rows, Measure on Rows

D. For sales: Measure on Rows, Dimension on Rows; For profit: Measure on Columns, Dimension on Columns

Solution

1. Step 1: Set up horizontal bar chart for sales

   Horizontal bars require dimension on Rows and measure on Columns.

2. Step 2: Set up vertical bar chart for profit

   Vertical bars require dimension on Columns and measure on Rows.

3. Step 3: Match options to setup

   For sales: Dimension on Rows, Measure on Columns; For profit: Dimension on Columns, Measure on Rows correctly assigns shelves for both charts.

4. Final Answer:

   For sales: Dimension on Rows, Measure on Columns; For profit: Dimension on Columns, Measure on Rows -> Option B

5. Quick Check:

   Horizontal bars = dim rows, measure columns; Vertical bars = dim columns, measure rows [OK]

Hint: Horizontal bars: dim rows; Vertical bars: dim columns [OK]

Common Mistakes:

• Using same shelf setup for both charts
• Placing measures on wrong shelves
• Confusing dimension and measure roles