Data Visualization

Lecture 8

Data Visualization

Historically, data visualization served to make hidden relationships comprehensible or complex ones visible.

The advent of informatics tools has let scientists• easily and rapidly generate of visualizations;

• view their data through several lenses;

• even interact with their data in novel ways;

• make sense of high dimensional data sets such as those from microarrays; and

• see more data in finer detail than before, as with MRIs.Moreover these tools serve as cognitive aids, reducing the need to hold multiple data representations in memory.

Cholera in the Age of Snow

John Snow’s (1854) plot of cholera deaths illustrated the link between cholera and the Broad Street water pump.

Minard’s Perspective on Napolean’s Defeat

Charles Minard’s (1869) map of Napolean’s Russian campaign illustrates the extent of his army’s loss.

Data Visualization Software

Scientists across disciplines rely on software that displays the structure, dynamics, and interactions in their data.

Informatics tools may specialize on a particular type of data or a particular scientific field, as with• structural and functional MRI results,

• data in geographical information systems,

• molecular structure and chemical properties,

• astronomical measurements and imagery.Other informatics software provides general charting and plotting capabilities.

mri3dX

mri3dX analyzes and displays voxel data from MRIs.

http://imaging.aston.ac.uk/mri3dX/

ArcGIS

ArcGIS lets scientists display and analyze data with important geospatial components.

Laying historical tornado paths on urban maps.

Viewing the land use of a region.

http://www.esri.com/

Visual Molecular Dynamics

VMD displays complex molecular systems from x-ray diffraction and nuclear magnetic resonance data sets.

http://www.ks.uiuc.edu/Research/vmd/

Karma

Karma displays and analyzes astronomical data.

http://www.science-software.net/karma/

Spotfire

Spotfire displays high dimensional data, such as the microarray data set shown below, in multiple modes.

http://www.cs.umd.edu/hcil/pubs/screenshots/Spotfire/

Many Eyes

Many Eyes encourages collaborative visualization and interpretation of data sets.

Users upload data in tab-delimited formats and have access to several chart and graph options including• line graphs,

• network diagrams,

• tag clouds, and

• world and country maps.The web site includes features for • commenting on data and visualizations,

• sharing snapshots of visualizations,

• and building topic communities.

Many Eyes

http://manyeyes.alphaworks.ibm.com/

Motion Chart (aka Trendalyzer)

Motion charts plot multi-dimensional time series data and animate their dynamics.

Motion charts are accessible through Google Docs, Google Gadgets, and the Google Visualization API.

View examples online at

http://www.gapminder.org/

Motion Chart Use at Gapminder