DATE & TIME:   Friday, September 26th;   10:00 am
LOCATION:   W272 Lagomarcino

SPEAKER:  
Graham Wills,  SPSS, Inc.

TITLE:
"Specifying the Grammar of Graphics"

ABSTRACT:

The "Grammar Of Graphics" is a system invented by Leland Wilkinson for describing statistical graphics using an algebra approach. Unlike many of the taxonomies of statistical and general visualization systems, the grammar is also prescriptive; any well formulated expression defines a resulting graph. However, from the user's point of view, the grammar is insufficient to define visualizations with the precision that is often required. For example, the chart defined by "FRAME: date, GRAPH: point()" defines a dot plot of the date variable, but the details of presentation are left vague. If we asked several people to draw such a chart (or, indeed, if we asked several different charting applications) we will likely find the end results looking somewhat different. In this talk I will present ViZml, a markup language that allows precise specification of graphs within the framework of the grammar. This system is the core of the new SPSS 12 graphics facility (released just last week) and combines core grammar concepts with extended properties and Cascading Style Sheet (CSS) definitions to provide a tool for advanced visualization specification.


REFRESHMENTS:  
9:45 am;   104 Snedecor Hall