Details

Voronoi Treemaps - The technology behind

Treemaps were established by Ben Shneiderman from Maryland in the mid 90's to display hierarchical data using nested (rectangular) areas. Each branch of a classification hierarchy is represented by a rectangular area. Subbranches tile them into rectangular subshapes and so on. This efficiently uses available screen space but the use of rectangular shapes makes perception of hierarchical structure difficult. Voronoi treemaps replace the rectangular areas by convex Voronoi shapes (Balzer & Deussen).

These shapes provide improved visual perception of hierarchy levels and related entities. When applied to a regulatory classification scheme from bacteria, the layout of a section of a treemap looks as follows:

In a similar manner layouts based on Voronoi treemaps can be applied to any imaginable functional classification system.

Changes in expression levels for genes or proteins are visualized using a color gradient. Multivariate data (expression change combined with uncertainty and amount of biomolecules) may be represented using gray shading (i.e. saturation - see figure) or variation of brightness.

Paver Viewer - Browsing Your Data

Paver Viewer is a read-only version that we deliver along with your processed data.

With Paver Viewer you can

• import a prepared and signed treemap,
• import data files matching the treemap,
• adjust color schemes and other treemap properties,
• zoom treemap in and out,
• zoom single clusters in and out,
• zoom label viewer in and out,
• save visible treemap in a variety of formats.

Development

Paver's underlying engine has been developed in a collaborative effort of DECODON and the group of Dr. Jörg Bernhardt at the Ernst-Moritz-Arndt-University of Greifswald bringing together expertise in software development, bioinformatics and OMICS centric biology.

Until now Paver and its underlying technology have been applied in molecular medicine (human cell lines, treatment of blood products), pathogenomics (host pathogen interaction, response of human cell lines to infection) as well as microbial physiology (B.subtilis, S.aureus strains, Pseudomonas strains) and MetaOMICS related studies.