A heat map is a visual representation of numbers in a table or a grid such that the bigger numbers are encoded by darker colors or bigger sizes and the smaller numbers by lighter colors or smaller sizes. This type of representation makes the reader's pattern detection from the data easier.
Let's use the same sample file, Sample – Superstore Sales (Excel)
. Open a new worksheet and select Sample – Superstore Sales (Excel) as the data source.
Once the data is loaded, perform the following steps to create a heat map chart:
When we created the chart for the first time, Tableau assigned various sizes to the square boxes, but when we placed Profit as a color mark, red was used for low amounts of profit and green was used for higher amounts of profit. This made spotting of patterns very easy. Binders and Binder Accessories, shipped by Regular Air in the Central region, generated very high amounts of profit and Tables, shipped by Delivery Trucks in the East region, generated very low amounts of profit (it actually created losses for the company).