AGOCG logo
Graphics Multimedia VR Visualisation Contents
Training Reports Workshops Briefings Index
This report is also available as an Acrobat file.
Next Back [Top]

Review of Visualisation Systems

9.3 IRIS Explorer

9.3.1 - SWOT analysis
9.3.2 - Comments

9.3.1 SWOT analysis



The version of Explorer used for this analysis was 2.0 running on Silicon Graphics equipment. All comments are based on this version unless otherwise stated.

Range of versions: Weakness

This is only a temporary weakness - SGI, SUN (SunOS) and IBM RS/6000 are available now, HP 9000/700 and SUN (Solaris) are promised by the end of the summer and DEC Alpha sometime after that. There is also a Cray version, and other supercomputer versions are being discussed.

Company stability: Strength

NAG have been in existence for over 20 years; their turnover is steadily increasing; their staff complement has been stable over the recent difficult period in the economy. It is not-for-profit so surpluses are fed back to the benefit of the company.

Costs: Strength

It is currently bundled with SGI workstations. This will change, but NAG Ltd. have publicly committed to a non-expensive pricing strategy. Educational sites will receive a 50% discount on both the one-time fee & the support service. Support costs will be approximately 15% of the one-time fee. Current SGI users, who up to now have received it free, will be offered support and maintenance for an unlimited number of users for the price of the 4-user support service up to Release 3.0. For the period of probably a year after Release 3.0, these sites will be offered the opportunity to increase the scope of their licence to include more users for the difference in support charge only. Those who do not take up the offer before Release 3.0, and new sites wishing to receive IRIS Explorer, will have to pay the one-time payment which ranges from 1000 for a single user licence to 20,000 for an unlimited user licence. These costs refer only to 1 implementation; an additional fee of 500 (licence) and 75 per annum (support) is charged per extra implementation.

Data input tools: Strength

DataScribe is a flexible, visual programming tool. It allows the user to easily create a data reader that will convert from any data file format to an Explorer data type. This does require, however, knowledge of the data file format and some knowledge of Explorer data types and their uses. DataScribe can also be used in reverse to output data from IRIS Explorer according to any desired format. Indeed, it can be used as a general data conversion tool between two external formats.

Data readers: Strength

A range of readers are provided (e.g. AVS types, HDF, PDB, Plot3D). Others (e.g. ReadMarc, ReadMesh1, ReadMultiPlot3D, ReadNastran, ReadSEGY) are available as either unsupported (they come on the installation disk, but are user donated modules) in version 2.2 or available through Explorer ftp sites (e.g. netCDF).

Video capability: Strength

Facilities to animate the viewing position are provided; and there are loop controls in the visual programming language. There are modules to control a video recorder; and a module to interface to MovieMaker on SGI.

Hardcopy: Weakness

At present, it does not seem possible to generate CGM. Postscript is only available through the Render module: it will generate colour Postscript with options to set an output size in inches and setting the DPI; it can be sent direct to a printer or into a file. It is also possible to output GIF.

Documentation: Strength

Detailed manuals (in the form of a User's Guide, Module Reference Manual and a Module Writer's Guide), plus on-line help (UNIX man pages) for Explorer subroutines and on-line help pages with each module.

Support: Strength

IRIS Explorer Centres have been established in the UK and Japan, and there is support in the US. These act as one-stop shops for the product. The support service licence also includes phone/fax/E-mail support, Users Newsletter and regular CDs containing tested and implemented modules. Also NAG Bulletin Board is a source of up-to-date information with an IRIS Explorer section; this is available on WWW at:

Usability: Weakness

IRIS Explorer (for the naive user) needs some time to learn, and is not suitable for the occasional user (who would be better with a menu driven system). Conversely its flexibility makes it highly usable by the expert. It needs a workstation of reasonable processor power and memory for worthwhile use.

Functionality: Strength

Distributed support: Strength

The design of IRIS Explorer is focussed on a distributed execution model. It is easy to place computationally intensive modules on separate compute engines. The Render Remote module explicitly provides for rendering to be carried out on a separate workstation. At present, on SGI, it uses GL rather than X so remote execution with local viewing can be a problem. Version 2.2 and above uses OpenGL so remote viewing is no longer a problem (with IRIX5 and above).

Customisability: Strength

IRIS Explorer has two important customisation features:- (1) Module Builder is a visual programming tool that allows the user to write their own code and then compile it into a new module. (2) Modules can be grouped to provide simpler interfaces for novice users (cf turnkey).

Command language: Weakness

IRIS Explorer provides a command language called SKm (scheme) which can be run interactively or from a script file. The language allows the functionality of the map editor with the launching/destroying of modules, connection/disconnection of ports, the setting of parameter values and loading/saving maps etc. It is also possible to define procedures involving modules and values. The system allows a limited form of batch working.


A state of the art visualization system from a UK company with a long history of supplying the higher education community with high quality software. IRIS Explorer is an application builder which makes it highly flexible as a visualization tool. It uses a visual programming interface to build networks of modules to form visualization maps, it allows the incorporation of new/user written modules to extend the functionality if the need arises and it supplies tools to aid the generation of these new modules.

There are options to extensively customise the appearance of maps by grouping the modules together and allowing the user to define their own control panel by selecting and re-arranging widgets. This customisability is extended by allowing these groups to be saved and used by other, more novice, users as turnkey applications.

One of the strengths of the IRIS Explorer software is that the system architecture was explicitly designed to ensure its application across hardware platforms in heterogeneous network environments. This, combined with NAG's expertise in porting software, will ensure that the user is able to fully exploit the easy to use remote module execution system of Explorer for distributed working.

Explorer provides a good graphical user interface, DataScribe, for writing data import modules. Although it is difficult for novice users and applies only to Lattices it is still a powerful tool with many useful features. These features should allow Explorer to do well with respect to the increase in competition.

The down side, as with most other flexible systems, is the rather steep learning curve. Also a lack of good hardcopy output, this being a screen dump only available from the render module in encapsulated postscript format, and a poor command language do not do it justice.

Review of Visualisation Systems
Next Back [Top]

Generated with CERN WebMaker

Graphics     Multimedia      Virtual Environments      Visualisation      Contents