Scientific VisualizationScientific Visualization

CS 521CS 521

Spring ’05Spring ’05

Eli, Drew, ShazEli, Drew, Shaz

IntroductionIntroduction SciVis utilizes computer graphics, image SciVis utilizes computer graphics, image

processing, signal processing as processing, signal processing as techniques to analyze numerical data.techniques to analyze numerical data.

It makes it much easier to understand It makes it much easier to understand results of complex numerical data analysisresults of complex numerical data analysis

The visualization helps scientists to The visualization helps scientists to interact and investigate with certain interact and investigate with certain aspects of the data.aspects of the data.

What it is?What it is?

The methodology of quickly and The methodology of quickly and effectively representing data.effectively representing data.

Humans perceive better than machines, Humans perceive better than machines, and machines calculate much more and machines calculate much more consistently and accurately.consistently and accurately.

It is a combination of graphics It is a combination of graphics capabilities in the 21capabilities in the 21stst century with century with human perception. human perception.

The NeedThe Need

Ability to deal with the randomness Ability to deal with the randomness included in natures equations.included in natures equations.

The larger amounts of test data The larger amounts of test data capability, results of which are capability, results of which are normally harder to see.normally harder to see.

The largest test data available to us is The largest test data available to us is one nature provides us with.one nature provides us with.

Quality Vs. QuantityQuality Vs. Quantity

QuantityQuantity Provides a bigger pictureProvides a bigger picture Play with the whole data setPlay with the whole data set

QualityQuality Ability to slice a subset of the data set.Ability to slice a subset of the data set. Detail – orientedDetail – oriented

HistoryHistory

Three stages of mdmv Three stages of mdmv (multidimensional multivariate (multidimensional multivariate visualization) developmentvisualization) development

Searching stage (1782 – 1976)Searching stage (1782 – 1976)

Awakening stage (1977 – 1985)Awakening stage (1977 – 1985)

Discovery stage (1987 – 1991)Discovery stage (1987 – 1991)

Searching stageSearching stage

Mdmv was to be studies long before Mdmv was to be studies long before computer science by statisticians computer science by statisticians and psychologistsand psychologists

All studies were in 2D xy displays All studies were in 2D xy displays due to lack of technology.due to lack of technology.

Awakening stageAwakening stage

Tukey came out with data analysis Tukey came out with data analysis methodsmethods

2D and 3D spatial data was commonly 2D and 3D spatial data was commonly studied during the time.studied during the time.

It was not just a tool anymore but a It was not just a tool anymore but a way of understanding how to decode way of understanding how to decode datadata

Discovery StageDiscovery Stage

Moved away from just data analysis to Moved away from just data analysis to very high graphical visualizations very high graphical visualizations which required a lot of computation which required a lot of computation power.power.

Virtual reality brought new meaning Virtual reality brought new meaning to visualization techniques.to visualization techniques.

NFS declared the need for 2D/3D NFS declared the need for 2D/3D spatial visualization.spatial visualization.

BreakdownBreakdown

Independent variable – DimensionIndependent variable – Dimension Dependent variable – VariateDependent variable – Variate Equation – Equation –

Y = f(x)Y = f(x)

Y is dependent on XY is dependent on X

2D Visualization Example2D Visualization Example

Example of 2D Example of 2D visualization visualization (charts) most (charts) most commonly used in commonly used in business business applications.applications.

3D Visualization Example3D Visualization Example Reynard Motorsport Reynard Motorsport

Engineers recognized Engineers recognized as leader in Formula 1 as leader in Formula 1 and Indy car design and Indy car design use Ensight to study use Ensight to study airflows.airflows.

Voith hydro to design Voith hydro to design more efficient more efficient hydroelectric turbines hydroelectric turbines less harmful to fish.less harmful to fish.

MotivationsMotivations

The availability of increasingly The availability of increasingly powerful computers with extremely powerful computers with extremely fast internal and external memory.fast internal and external memory.

Compresses a lot of data into one Compresses a lot of data into one picture (data browsing).picture (data browsing).

Reveals co-relations between different Reveals co-relations between different quantities both in space and time.quantities both in space and time.

Possible to view data selectively and Possible to view data selectively and interactively in ‘real time’.interactively in ‘real time’.

FoundationsFoundations

Spatial – orientedSpatial – oriented Still graphs used, all relevant data is Still graphs used, all relevant data is

displayed at the same time in a given displayed at the same time in a given spacespace

Multiple view vs. multiple symbolMultiple view vs. multiple symbol Multiple view – one display panel shows values Multiple view – one display panel shows values

of multiple variables simultaneouslyof multiple variables simultaneously Multiple symbol – Only one symbol is used but Multiple symbol – Only one symbol is used but

conditional relationships are shown in multiple conditional relationships are shown in multiple panels.panels.

ExampleExample

FoundationsFoundations

Temporal OrientedTemporal Oriented Also known as Kinematic displays Also known as Kinematic displays

(Tukey and Tukey 1988)(Tukey and Tukey 1988) Variations across time are utilized to Variations across time are utilized to

depict higher dimensions instead of depict higher dimensions instead of using all variables within given space using all variables within given space and time.and time.

ReferencesReferences

http://pareonline.net/getvn.asp?v=8http://pareonline.net/getvn.asp?v=8&n=17&n=17

http://www.cse.ohio-state.edu/~crawhttp://www.cse.ohio-state.edu/~crawfis/cis694L/fis/cis694L/

SciVis presentation of spring ’03 SciVis presentation of spring ’03 CS521CS521

http://www.ceintl.com/industries/indhttp://www.ceintl.com/industries/industries.htmlustries.html