This report is also available as an Acrobat file.

[Top]

Review of Visualisation Systems

Annex to Chapter 9:
Strengths Weaknesses Opportunities Threats

9.6 IBM Data Explorer

9.6.1 - Introduction
9.6.2 - Additional Information for IBM Data Explorer
9.6.3 - Data Manipulation

9.6.1 Introduction

During the review of the visualization systems an in-depth SWOT analysis was not performed for IBM Data Explorer. This omission should not be taken as a reflection on the features provided by the IBM Data Explorer system. This annex will provide similar information for IBM Data Explorer that can be found in chapter 9 for other visualization systems. This annex will either provide that information under the equivalent section headings or references to other areas in this report where that information can be found.

The final section of this annex contains some information on the powerful data manipulation facilities available in IBM Data Explorer.

9.6.2 Additional Information for IBM Data Explorer

Range of versions

IBM Data Explorer is available on a range of Unix workstations and the complete range of versions can be found in section 8.3.1 on page 111.

Company stability

International Business Machines Corporation (IBM) has a long history in the computing industry and is involved in almost every area of computing hardware and software. For more specific information on the company and products you can access the IBM WWW home page:

http://www.ibm.com

Costs

Price information can be found in section 8.3.1 on page 111.

Data input tools

Information concerning importing data into IBM Data Explorer can be found in section 3.2.3 on page 24 and section 4.3 on page 66.

Data readers

Information on data readers and their location can be found in section 4.3 on page 66

Hardcopy and Animation Facilities

These features are detailed in section 5.2 on page 80.

Documentation

The full range of manuals are listed in section 8.3.3 on page 112.

Support

Contact addresses and arrangements for support are in section 8.3.2 on page 112.

Functionality

A review of the functionality in IBM Data Explorer can be found in section 3.2.3 on page 24 and some information on data manipulation is contained in section 9.6.3.

Distributed working

Details of these facilities can be found in section 7.2 on page 103.

Customisability

Information on incorporating application code into the IBM Data Explorer system can be found in section 6.3 on page 92.

Command language

IBM Data Explorer has an extensive scripting language. To execute IBM DX in script mode you simply type:

dx -script

More details on the scripting language can be found in the IBM Data Explorer User Guide [26].

9.6.3 Data Manipulation

Sometimes the scientist using the visualization system wishes to select a subset of the data to process or wants to apply an expression to the dataset to produce a resultant data component e.g., vector magnitude from a vector field. Most of the visualization systems provide support in the form of modules to slice and crop the data and other modules to apply simple mathematical expressions to data components.

If the scientist however wants to select specific data components from a dataset based on some conditional expression then there is only minor support through modules in the various systems. The user must resort to coding the task in the form of an additional module if any extensive manipulation is required for example see [64].

IBM Data Explorer provides extensive support for both of the above cases through the Compute module. This module applies an expression point-by-point to the input data producing an output dataset. The module also allows multiple input fields to be combined via the expression supplied and individual data components within a dataset can be referenced in the expression. Some of the operations available in the Compute module are:

Trigonometric, Hyperbolic and Logarithmic functions
Unary, Binary and Vector functions
Type conversion
Logical and Conditional expressions
Bitwise operations

The user can construct complex expressions for example, Field1 is a vector field, Field2 and Field3 are scalar fields. The expression evaluates on a point-by-point basis an output field which is the magnitude of Field1 added to the quantity Field2 divided by 4.5 times Field3:

output_field=Compute("mag($0) + $1/($2*4.5)", Field1, Field2, Field3);

More information on the Compute module can be found in [27].

Review of Visualisation Systems