# Tableau Tip: Visualize a Single Value Against Others

guest_blog 12 Jul, 2020
4 min read

## Introduction

How often have we all tried to compare a value against a range, with unsatisfying results? Excel is the most common tool for data visualization, due to the fact that more than 1.2 billion people around the globe are using Excel [1]. Nonetheless, Excel has limitations in data visualization. The solution to these limitations is Tableau.

In this article, we are going to build an efficient chart that compares a single value against a range of values.

Tableau Chart showing single values against ranges.

## Problem Statement

Let’s suppose that we have prices for different Products (Table, Chair, Lamp, Sofa, Bed) sold in a specific Shop (A, B, C, D, E, F). The scope is to compare Prices placed from the Shop A with those set from the Other Shops (B, C, D, E, F).

Input Data in Tableau.

## Steps to Build a Chart

1. First, we need to create two Calculated Fields to isolate Shop A from the others.
• PRICE_1, the price of the products from Shop A — using

`IF [Shops]="A" THEN [PRICE_1] END`

• PRICE_2, the price of the products from the other shops — using

`IF [Shops]!="A" THEN [PRICE_2] END`

2. Secondly, we need to define the range’s boundaries by calculating the minimum and maximum value by product type, but only for the Other Shops (i.e., excluding Shop A).
• The upper bound, MAX_PRICE — using

`{ FIXED [Product] : MAX (PRICE_2) }`

• The lower bound, MIN_PRICE — using

`{ FIXED [Product] : MIN(PRICE_2) }`

FIXED is extremely useful as, together with MIN or MAX, it allows us to find the minimum/maximum value for each Product category. It aggregates the value at the specified dimension.

Now we are ready to create our chart!

## Building the Chart

Let’s drag and drop Product in the Row Field, PRICE_1 in the Column Field, MAX_PRICE and MIN_PRICE in the Marks Field.

Note the Row Field/Column Field and the Marks Field.

MAX_PRICE and MIN_PRICE must be changed from SUM to ATTR.

By default, Tableau will create a bar chart — which is not what we need!

Under the Marks Field, we need to change the chart type from Automatic to Circle.

### Show a Range using Reference Lines

Right-clicking on chart axes will show us axis edit options.

We then add a Reference Line, by Right-Clicking on the x-axis > Add Reference Line.

Settings for our reference line, using the Band option with ATTR(MIN_PRICE) and ATTR(MAX_PRICE)

A new window will appear. Here, select the same options as shown in the screenshot above.

The final step is to add a color indication to tell us whether the value is inside (green) or outside (red) our range.

#### Dynamic Point Colors

We create another Calculated Field named IN/OUT:

``````IF ([MIN_PRICE])<[PRICE_1] AND [PRICE_1]<([MAX_PRICE]) THEN "TRUE"
ELSE "FALSE"
END``````

IN/OUT is added to the Marks field

We drag and drop IN/OUT to Color under Marks — and we change the colors as desired!

Although there are several calculations, the result is a huge improvement over what we can achieve with Excel or the default Tableau charts.

I have used this chart style time and time again — it is incredibly versatile. I hope you will find it as useful as I do!

Thanks for reading.

## References

[1] J. Osborne, Build 2016: the biggest news from Day 1 and 2 (2016), Techradar

### About the Author

Laura is a Financial Analyst, who strongly believes that data visualization is the best way of analyzing both big and small datasets. I love learning new things and challenging myself to learn new methods and technologies to help me be a better analyst.

guest_blog 12 Jul, 2020