ActiveGEM Package


The ActiveGEM family of applications is designed for research-oreinted meterological applications. The graphical user interfaces (GUIs) that make up ActiveGEM provide user-friendly low-level control over the powerful General Meteorolocal Package (GEMPAK), widely used for graphical and diagnostic applications in the atmospheric sciences. The graphical environment of the AcitveGEM utilities ensures that the user has the maximum flexibility within each GEMPAK application, and ties many of the applications together seamlessly so that the user is abstracted from the implementation of the GEMPAK functions themselves. A comprehensive options list, along with explicit override definitions in each application, ensures that the user can do anything that the underlying software can do with a minimum of scripting expertise. ActiveGEM has been designed for compatibility with GEMPAK versions 5.6 and later, although backwards compatibility to earlier versions is likely.

If you feel that you would like to make a donation to this project, the developers and users of ActiveGEM would greatly appreciate your generous support. Although developers and debuggers devote their time to the project for free, there are costs involved with development and support which would be greatlfully shared with any willing supporters. For more information on how to make a donation to the ActiveGEM package, click on the PayPal link.

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The current version of ActiveGEM includes only a single application: plotGEM. This GUI greatly simplifies plotting procedures for GEMPAK files for plan, cross-section and profile plots.. Further developments to the package will result in a diagnostically-oreinted GUI which will minimize the amount of shell scripting required for simple diagnostics of multiple files.

plotGEM GEMPAK Plotting GUI

The plotGEM GUI simplifies access of the plotting programs and functions provided with GEMPAK. Current graphical interfaces (e.g. NAWIPS) offer an operational level of flexibility, but do not allow for the level of customization required by research-oreinted users. The notebook-style interface allows the user to load any file (or group of files) and creates a selectable list of the all of the fields held within the input file(s). Depending on the type of input field (user has the choice of "scalar" or "vector" field plotting of fields or functions), notebook pages provide a comprehensive list of the options available for plotting of the selected data. Full menus and popup windows allow the user to completely describe background mapping and gridding options for plan plots. Further notebook pages allow the user to set options for cross-section and profile plotting, modes which are selected by highlighting the appropriate menu entry. The full superposition capabilities of the GEMPAK programs are reproduced in stack-based form in the interface. The final notebook pages contains a complete suite of user-overrides, each of which can be activated to fine-tune behaviours not reproducable within the broad limitiations of the GUI. The overrides ensure that the user never needs to enter the GEMPAK text interface, since all of the flexibility (any dynamic help messaging) is provided within the graphical environment.

Full documentation of the plotGEM utility is provided with the ActiveGEM online manual or downloadable manual.

This screenshot shows the File I/O main (entry) page of plotGEM, where the stack-based file accessing and output file naming options are set.

This screenshot shows the profile plotting options in plotGEM. Note that superposition mode is active, and than a plan plot will be generated in this case (selectable under the "Type" menu). Separate windows are opened for advanced options using the "More" and "Background/Markers" buttons on the right side of this page. Graphical selection of the profile location (as with cross-section and zooms on the plan plots) are one of the most powerful easily-used features of the GUI).


The latest version of the ActiveGEM source package is available for download from the project summary page on the SourceForge servers. Documentation for the latest version is available in either online or downloadable format. A quick-reference guide (single sheet) is available in Open Office Writer, MS Word, PDF, or online format. An introductory presentation is also available in either MS PowerPoint or Open Office Impress format.


The ActiveGEM family of programs has been under constant testing and development since its creation by Ron McTaggart-Cowan in 2003. The GUIs distributed with the package are written in Perl/Tk, an interface between the standard perl language and Tcl/Tk. Some segements of the package are also written Fortran90 and Fortran77. Anyone with expertise in development using any of these languages is encouraged to help with the ActiveGEM package. Although complete bug reports are much appreciated, bug fixes and program enhancements are of even more value in the development process. Please contact our admin to volunteer to help to build and maintain ActiveGEM.

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