Table of Contents
What is a Heat Map
Heat Maps 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.
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 Inline Chart query builder.
- Set any numeric columns to Heat Maps – Heat Map.
- From the Heat Map toolbar button, select either Zero-Based or Median-Based map.
- From the same Heat Map toolbar button, select either Simple or Complex map.
- All selected column values will be considered together to internally determine the “half”.
- Minimum and maximum values appear in bold.
Heat Map Demo Queries
Look for the ready-to-use Zero Complex Heat Map and Median Simple Heat Map generated queries under the Queries > Demo Queries > Inline Charts > Heat Maps folder. Click on the “add demo queries” command link, if not there.
All Heat Map demos use random values, so you will likely get a different image every time. Here is a custom Median-Based Complex Heat Map, built with fixed values:
Customize your Heat Map
- Switch between a Zero-Based and Median-Based map.
- Switch between a Simple and Complex map.
- Hide the text in any inline chart cell.
- Show cells as monochrome, with no colors.
- 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.