GGobi

Infobox programming language
name = GGobi

paradigm =
year =
designer =
developer = Deborah Swayne, Michael Lawrence, Hadley Wickham, Duncan Temple Lang, Di Cook, Heike Hofmann and Andreas Buja
latest_release_version = 2.1.7
latest_release_date = September 29, 2007
latest_test_version =
latest_test_date =
typing =
implementations =
dialects =
influenced_by =
influenced =
operating_system = Windows, Macintosh, Linux
license =
website = http://www.ggobi.org/

GGobi is a statistical software tool used for graphing various types of data. GGobi allows extensive exploration of the data with dynamic graphics. It is also a tool for looking at multivariate data. R (programming language) can be used in sync with GGobi. GGobi prides itself on its ability to link multiple graphs together. [XGobi is listed on Michael Friendly's [http://www.math.yorku.ca/SCS/Gallery/milestone/sec9.html Milestones of Statistical Graphics] webpage.]

Overview

GGobi was created to look at data matrices. The designers were interested in exploring multi-dimensional data. The program developers went through many name changes before settling on GGobi. The original concept, Dataviewer, began in the mid-80s, and a predecessor, XGobi, began in 1989. Work began on the current version of GGobi in 1999. The main reason for the different versions was the change in technology.

Released under a combination of three free software licences, GGobi is free software. [cite web
url=http://www.ggobi.org/licenses.html
title=GGobi licences page]

GGobi Topics

Importance of graphics

Looking at data through various graphs can reveal more information about the distribution than just looking at the numbers or a summary of them. Using the different tools within GGobi, clusters, non-linear distributions, outliers, and other important variations in the data can be discovered. GGobi is a program which allows exploratory data analysis to occur for multi-dimensional data.

Types of graphics

* 1D: Average shifted histogram, textured dot plot, barchart, spineplot
* 2D: Scatterplot
* High-D: Scatterplot matrix
* High-D: Parallel coordinates
* High-D: Grand tour, projection pursuit guided tour, manual tour
* Time series plot

Interactions

These tools can be used to pick out special points or clusters of data.
* Brushing: As the brush moves over a point, the point will be highlighted.: If "persistent" is selected, the points the brush has moved over will remain "painted".
* Identify : As the cursor moves over a point, a label, or variable value will appear at the top of the graphic screen.
* Linking: Multiple plots are linked so identifying one point in one plot will identify the same point on all other graphs, and brushing a group of points in one plot will highlight the same points in other plots. The linking can be one-to-one, or according to the values of a categorical variable in the data set.
* Moving points: Points in a plot can be moved interactively, eg to gauge results from multidimensional scaling.
* Add/remove points or edges.

References

Further reading

* Buja, A., D. Cook, and D.F. Swayne (March 1998). "XGobi: Interactive Dynamic Data Visualization in the X Window System". in: "Journal of Computational and Graphical Statistics" 7 (1): 113–130.
* Buja, A., D.T. Lang, and D.F. Swayne (August 28, 2003). "GGobi: Evolving From XGobi into an Extensible Framework for Interactive Data Visualization". In: "Journal of Computational Statistics and Data Analysis" 43 (4): 423–444.
* Cook, D. and D.F. Swayne (2007). "Interactive and Dynamic Graphics for Data Analysis". Springer.

External links

* [http://www.ggobi.org GGobi Data Visualization System]
* rggobi is an [http://www.R-project.org R] package that interfaces R and GGobi.

* References to GGobi on the web include links at Humboldt University [http://statwiki.wiwi.hu-berlin.de/index.php/GGobi] , Ubuntu [http://packages.ubuntu.com/de/hardy/math/ggobi] , Debian [http://packages.debian.org/de/etch/ggobi] , Freshmeat [http://freshmeat.net/projects/ggobi/] , Hugh-Public [http://florence.acadiau.ca/collab/hugh_public/index.php?title=GGobi_Intro] , Softpedia [http://linux.softpedia.com/progDownload/GGobi-Download-29683.html] .