Back to: Articles | Learning Center
|
|
What Is A Heat Map?
A heat map is any data visualization which uses color to represent data values in a
two-dimensional image. There are many different types of heat maps used in different disciplines,
each refered to by the term "heat map", even though they use different visualization techniques.
Most heat maps use mapping techniques to represent their data rather than charting and graphing
techniques, thus providing unique views of data not available in charts and graphs.
This article examines the most common types of heat maps and when each is used. The type of
heat map used by Lab Escape's Heat Map Explorer and Enterprise Tree Map SDK products is a tree map,
which is the most common type of heat map in the business world.
|
|
|
|
|
|
Tree Maps
Tree maps, or "treemaps", are the most common type of heat map.
Used to represent large or complex data sets in applications ranging from stock market
analysis, risk management, project portfolio analysis, market share analysis and network management,
tree maps were invented by Ben Shneiderman at the University of Maryland in 1990.
Tree maps maps give you an edge in identifying critical issues, allocating resources, finding trends
or relationships and creating transparency in large or complex data sets. Tree maps do this by showing
the line item details of a dataset in a way that also provides a visual summary overview, so that trends,
anomalies, distributions and relationship can be seen in context and at multiple levels at once.
Tree maps look like a series of nested rectangles, where each
rectangle represents an item in a set of data. Data values can be mapped to both the size
and the color of each rectangle, allowing users to analyze two variables at once. Grouping rectangles
together provides an intuitive way to visually analyze categorized, segmented or multi-dimensional data.
For more information about tree maps, please watch our presentation
Gaining an Edge Using Heat Maps, download
a free trial version of Heat Map Explorer, or
contact us at (800) 921-3623 or .
|
|
|
|
|
|
Geographic Maps
Geographic maps are one of the oldest types of heat maps, though only recently has the term
"heat map" started to be applied to these visualizations.
Used to represent location-based data, geographic heat maps highlight trends, anomalies and
distributions across a geographic area in application rangings from market share analysis, risk
distribution analysis, and real estate market analysis.
Geographic heat maps use one of two different heat map techniques to represent data. The first
takes each entity on the map, such as a country or state, and colors that entity with a single color
which represents the data value for that entity (see image above). The second technique uses a
topographic mapping approach similar to click maps and colorizes areas of activity, such as rainfall,
as clouds of color on the map.
Geographic heat maps are an excellent way to identify geographic trends and anomalies in
data. Additional, spatial maps, which are closely related to geographic maps, can be used to
visualize any data which is location-specific, such as mapping where products are sold in a retail
store or the usage patterns of machines on a factory floor.
While Lab Escape does not sell geographic or spatial maps, our salespeople have experience in this
area and can recommend a solution for your needs. For more information, please call us at
(800) 921-3623 and press 1 for sales or e-mail .
|
|
|
|
|
|
Microarray Maps
Microarray maps are a special type of heat map used to highlight gene expression in molecular biology.
Microarray heat maps use a colored grid linked by a dendrogram (a tree diagram) to hierarchically cluster genes.
Generally, the rows of a microarray heat map represent genes with each column of that row representing a
different sample. Each cell is colorized based on the level of expression of that gene in that sample.
Microarray heat maps help you find groups of genes which behave similarly across a set of experiments.
For more information on microarray heat maps, please visit the
Heat Map Builder produced by the Quertermous Lab
at Stanford University.
|
|
|
|
|
|
Summary
There are many different types of heat maps. This article listed just a few of the most common types.
Heat maps also can be created using self-organizing maps, business process diagrams and other types of
visualizations. What all heat maps have in common, however, is the powerful use of color to communicate
underlying data values which would be much harder to understand if presented numerically.
If you have any questions about heat maps, please feel free to contact Lab Escape
at (800) 921-3623 or e-mail
.
|
|
|
|
|
