Mercury

Description

• Provides Windows clipboard support for Gauss for both data and text.
• Provides Gauss functionality for Excel. Given a set of data in an Excel Workbook, Gauss will take the data, process it, and return the results to the specified cells in the spreadsheet.
• A set of communication and message tools for developers who need to link Gauss to an external application using custom interfaces.
• A demonstration project showing how Gauss compliant DLLs are created.

Features

Clipboard Support

Mercury provides a means of communicating data or strings between Gauss objects and the Window clipboard. For example, a section of a spreadsheet could be selected and copied to the clipboard in the usual fashion. This data could then be pasted directly into a Gauss matrix (x) using the Gauss command:
 
x = paste;
Similarly, a Gauss matrix, x,could be copied to the clipboard using the command:
 
call copy(x);
x could then be pasted into a spreadsheet or wordprocessor. For the former, if x were an n by k matrix, then the spreadsheet array would also be n rows by k column For the wordprocessor, the matrix has the form of tab delineated elements, again with n rows and k columns.

Excel Support

Excel_Link is an interface which binds an Excel application with Gauss -- in effect providing the functionality of dynamic data exchange. Data from the current spreadsheet is made available to Gauss using the Gauss command:
 
x = excelget(sheet, range);
and thus the components of the spreadsheet are simply an extension of the Gauss workspace. After processing the data, results can be placed back into the spreadsheet using the command:
 
call excelput(rslt, sheet, range);
Hence all the power of Gauss is available for mathematical computation and analysis, while the spreadsheet provides the advantages of data presentation and charting. The net effect is to have the functionality of Gauss within Excel. The Excel_Link application includes a working example, a Windows help system, and the full source code. Click the image for a screen shot of Excel_Link, and here for the Gauss code.

Communication Support Tools

Mercury provides a library of communication and messaging tools for programmers who wish to make use of the power of Gauss as part of an integrated system in which data and message transfer to and from Gauss is required, and which is to be controlled by an external application. These tools consist of a set of libraries and DLLs on the Gauss side, and a set of Visual Basic libraries and standard Windows APIs on the external side. These libraries permit sending messages, parameters, strings, values and data between the external application and Gauss, as well as routines for status checking status. A demonstration Visual Basic project -- VB_Link -- is included which shows how these calls are implemented. Click the image for a screen shot of this demonstration project. In addition, the Visual Basic project for Excel_Link is also included. While we have used VB for demonstrating these procedures, the ideas can be ported to any program that can access the Windows APIs -- for example C++, Delphi, Powerbuilder, etc. The code and DLL files are provided on a royalty free basis for use in your application.

Creating Gauss Compliant DLLs

Extensions to the GAUSS language is possible through custom DLLs. In effect, any code that one can write in C can become a Gauss procedure. Not only does this provide for really fast DO loops, but it also gives the programmer low level control over the operating system through the Windows APIs. In effect, this makes Gauss an open system. For example, the interface between Gauss and Gaussx, as well as all the components of Mercury rely on these extensions. A demonstration DLL project -- Testdll -- shows how such C code is written, and a step by step tutorial on how to create your own DLLs, running under Microsoft VC++, is also provided.