History of NCAR Graphics

The NCAR Graphics package has a long history and a bright future.

Decades of development

The NCAR Graphics package has been evolving since its inception in the early 1960s as a collection of low-level Fortran routines for drawing simple graphical elements on the output devices of that era.

In the 1970s, NCAR scientists and Scientific Computing Division staff developed higher-level graphics utilities which were integrated into a package that could be distributed throughout the scientific community. Portability was enhanced as the utilities generated an output metafile to achieve device independence.

In the 1980s, still more functionality was added, and the whole package was brought into conformance with the graphics and programming language standards that emerged at that time. In late 1986, the updated set of the NCAR Graphics utilities was converted to Fortran 77, the metafile was based upon a private encoding of the Computer Graphics Metafile (CGM) standard instead of the early home-grown metafile format, and the utilities were moved to the Graphical Kernel System (GKS) standard. This standards-conforming package has been distributed to about 1000 sites worldwide.

In the 1990s, the functionality of NCAR Graphics has been growing, both from the expanded power provided by GKS and from the addition of new utilities. With the release of NCAR Graphics Version 3.2 in 1993, a second programmatic interface was added: C program bindings were included for all calls to all utilities. NCAR Graphics is widely viewed as a mature two-dimensional visualization package.

New interfaces for the future

The traditional Fortran interface to NCAR Graphics can be difficult to use because it does not have a consistent user interface. This is because the various utilities were developed by numerous people through many years. Its components have been collected into one package, but new users of the package are often confused by the differences in the Fortran calls needed to control the various utilities.

The package is robust, it is widely used in the scientific community, and it provides a wide range of 2-D visualization capabilities. Rather than pursuing more 2-D or 3-D functionality, the NCAR Graphics Group is now focusing its efforts on improving the user interface.

This is why three new interfaces are being developed: High Level Utilities (HLUs), NCAR Command Language (NCL), and Graphical User Interface (GUI). When all three are fully implemented, NCAR Graphics will offer five user interfaces to all of its functionality.

The functionality in NCAR Graphics Version 4.1 is almost identical to that of Version 3.2, that is, the Fortran and C programmatic interfaces have not changed much.

The significant difference is that two new interfaces are partially implemented for a subset of the NCAR Graphics functionality. The High Level Utilities (HLUs) and the NCAR Command Language (NCL) are the beginnings of a consistent visualization model for all of NCAR Graphics.

In future releases, all NCAR Graphics functionality will be accessible through all three new interfaces.

NCAR Graphics developers have always strived to maintain compatibility between the many versions and releases of the NCAR Graphics package. It is our intention to keep supporting--for as long as possible--older user programs that were written for earlier versions of the package.

At Version 4.x, you should find that your existing Fortran and C programs that call routines in the NCAR Graphics libraries will continue to function as they always have.

If you notice functional discrepancies in the way your existing codes perform, you should contact your local site representative, and your site rep will determine if NCAR Graphics or SCD Consulting staff needs to be notified.

You might also consider joining an e-mail group of NCAR Graphics users and developers where a wide variety of usage issues are discussed and resolved. This group is called "ncarg-talk", and you can join by sending an e-mail message to Majordomo@UCAR.EDU with subscribe ncarg-talk in the body of the message (not the subject line). You can also contact a human by sending e-mail to ncarg-talk-approval@UCAR.EDU.

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