## Chapter 1. Overview

Partial Table-of-Contents

- 1.1 Overview of Data Explorer
- 1.2 System Structure
- Graphical User Interface
- Executive
- Modules
- Data Management
- How the Data Model Facilitates Interoperability

  This book describes the IBM Visualization Data Explorer`*`, which you can use in a workstation environment. Data Explorer is a visualization system that can be used in many application areas and with a variety of data representations to extract useful information from complex data.

  ## 1.1 Overview of Data Explorer

  The Data Explorer graphical user interface allows end users to perform tasks at various levels of sophistication. For example, a user can use the user interface to apply data and adjust input values to an existing visualization process. A slightly more advanced user can construct a new visualization process, called a visual program, by connecting a network of Data Explorer's modules. An expert programmer can create new modules, using C or FORTRAN, for use with the system modules. Besides the user interface, Data Explorer also provides a scripting language interface, for users who want to build their own visualization functions in a more traditional programming style.

  Data Explorer's graphical user interface provides an integrated online help facility. This facility provides users with online access to the Data Explorer user manuals, as well as with context-sensitive help information. In addition to the help information provided with Data Explorer, the online help facility allows users to document various aspects of their particular visual programs. Other users of these visual programs then have online access to this program-specific documentation.

  Data Explorer provides an extensive set of modules that you can use to visualize your data. For example, the Isosurface, Streamline, and AutoColor modules perform the standard visualization functions of creating constant-value surfaces, tracing particle paths through velocity fields, and coloring objects based on a data value, respectively.

  In addition to these expected functions, Data Explorer also provides tools to perform more sophisticated manipulation of data. The Map module is a general purpose module that can map a data field onto an arbitrary object--whether it is a streamline, an isosurface, or even another data field's computational mesh. The Compute module can perform arithmetic or trigonometric operations point-by-point not only on your data but also on the grid itself. Thus warping a grid, for example, is a simple matter of entering an expression.

  Even standard tools, such as Isosurface, operate on multiple types of input grids. For example, if the input field to Isosurface is 2-dimensional, the module automatically creates contour lines.

  The Data Explorer renderer can handle opaque or translucent surfaces, translucent volumes, and opaque or translucent lines or points--all in the same image. In addition, data on different computational or observational grids can be visualized together, allowing you to correlate disparate data fields without requiring you to force the data onto the same grid.

  The power and interoperability of the modules is possible because of the underlying data model, which is capable of describing a wide variety of types of input data. Because the data itself is self-describing, modules can be flexible in the types of data they accept, and can perform their actions appropriately based on their input.

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