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Glyph Fundamentals

Multivariate data (also called multidimensional or n-dimensional) consists of some number of points, m, each of which is defined by an n-vector of values.

Such data can be viewed as an mxn matrix, where each row represents a data point and each column represents an observation (also called a variable or dimension).

An observation may be nominal or ordinal, and may or may not have a distance metric, ordering relation, or absolute zero.

Each variable/dimension may be independent or dependent.

A glyph consists of a graphical entity with p components, each of which may have r geometric attributes and s appearance attributes.

Typical geometric attributes include shape, size, orientation, position, and direction/magnitude of motion, while appearance attributes include color, texture, and transparency.

Attributes can be discrete or continuous, scalar or vector, and may or may not have a distance metric, ordering relation, or absolute zero.

The list below (and Figure) give examples of glyphs from the literature and attributes controlled by the multivariate data point.


  
Figure 1: Examples of glyphs: variations on profiles; stars/metroglyphs; stick figure icons and trees; autoglyphs and boxes; faces; arrows and weathervanes.
\begin{figure*}
\centerline{\hbox{ %
\psfig{figure=profile.eps,width=1.75in}
\hs...
....75in}
\hspace*{.5in}
\psfig{figure=arrow.eps,width=1.75in}
}}
\par\end{figure*}



 
next up previous
Next: Glyph Limitations Up: A Taxonomy of Glyph Previous: Introduction
Matthew Ward
1999-02-08