Table of Contents
What is a Heat Map
Just like the equivalent rectangular Inline Heat Maps, and the Radial Heat Maps, Heat Map charts replicate with colors the “intensity” of some grid’s values: larger the value, darker the color. More specific, one lower “half” gradually gets the lighter colors, while the upper “half” gradually gets the darker colors. Both Heat Maps and Inline Heat Maps appear as walls of rectangular bricks, while the Radial Head Maps are rendered as nested doughnuts.
The term “half” is determined either by the zero value (for Zero-Based Heat Maps), or the median value (for Median-Based Heat Maps).
Simple Heat Maps will show just two colors: the up and down theme colors. First “half” – with lower values – gets the down color, while second “half” – with larger values – gets the up color.
Complex Heat Maps use a multitude of semi-transparent alpha values to gradually move from lightest to darkest, split right in the middle, where the “half” was.
Steps to Create a Heat Map
Start Visual Xtractor or Data Xtractor. Connect to a database. Create or design a SQL query. Run the query and check the results.
- Display and enable the Chart query builder.
- Set your numeric columns to Stacked Charts – Heat Map.
- From the Heat Map toolbar button, select Zero-Based or Median-Based map.
- From the same Heat Map toolbar button, select Simple or Complex map.
- All selected column values will be considered together to internally determine the “half”.
Heat Map Demo Queries
Look for the ready-to-use Median Complex Heat Map and Median Simple Heat Map generated queries under the Queries > Demo Queries > Charts > Bar Charts folder. Click on the “add demo queries” command link, if not there.
The demo queries also create equivalent rectangular Inline Heat Maps, but we’ll disable them for now…
Customize your Heat Map
- Change the drawing style.
- Hide the data labels.
- Switch between a Zero-Based or Median-Based map.
- Switch between a Simple or Complex map.
- Switch to 3D.
- Creating Heat Maps in Data Xtractor or Visual Xtractor is fast and trivial: just set one or more numeric columns as Heat Map.
- Choose either a Zero-Based or Median-Based map, which will determine the “half”.
- Choose either a Simple or Complex map, for two colors or many light-to-dark gradients.