18.4 Using MD*ReX

We will demonstrate the usage of M D *ReX in the context of quantitative financial modeling. In order to use M D *ReX a working installation of Excel 9.x is required. Furthermore the installation routine will setup a Java runtime environment and if needed a Virtual Java Machine. For more information please refer to http://md-rex.com/.

After successfully installing the client it can be used in two ways: for an on-demand usage M D *ReX can be accessed via the Start $ \rightarrow$ Programs shortcut in Windows or if a permanent usage in Excel is requested, the Add-in can be installed from the Extras $ \rightarrow$ Add-in Manager dialogue in Excel. The rex.xla file is located under

%Systemroot%\%Program Files%\MDTech\ReX\ReX.

In the latter case the client is available every time Excel is started. Anyway the client can be accessed via the Excel menu bar (Figure 18.1) and exposes its full functionality after clicking on the ReX menu item.

Figure 18.1: Excel and MD*ReX menus
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In order to work with M D *ReX the user first has to connect herself to a running XploRe Quantlet Server. This can either be a local server, which by default is triggered if M D *ReX is started via the Programs shortcut, or any other XQS somewhere on the Internet. Evidently for the latter option a connection to the Internet is required. The Connect dialogue offers some pre-configured XQS'. After the connection has been successfully established the user can start right away to work with M D *ReX .

In contrast to XploRe , the user has the option to perform statistical analysis by using implemented dialogues e.g. the Time Series dialogue in Figure 18.3. Via this dialogue a researcher is able to conduct standard time series analysis techniques as well as e.g. more refined nonlinear approaches like ARCH tests based on neural networks. These interfaces encapsulate XploRe code while using the standard Excel GUI elements hence undue learning overhead is minimized. Alternatively one can directly write XploRe commands into the spreadsheet cells and then let these run either via the menu button or with the context menu, by right clicking the highlighted cell range (Figure 18.2). Furthermore it is now much easier to get data to the XploRe Quantlet Server. Simply marking an appropriate data range within Excel and clicking the Put button is enough to transfer any kind of numerical data to the server. We will show this in the next section. A further virtue of using a spreadsheet application is the commonly built-in database connectivity. Excel for example allows for various data retrieval mechanisms via the Open Database Connectivity (ODBC) standard, which is supported by most of the database systems available nowadays.

Figure 18.2: ReX Context Menu
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