The add-ins in this package are programmed
using the Microsoft macro language, Visual Basic for Applications
(VBA). The source code is available for viewing and changing
when the add-in is installed in Excel. Some of the add-ins
are not password protected. These include the Teach DP and
Stochastic Models add-ins. They include specific model classes
that are provided through VBA subroutines. They are left
open so the user can add new problem classes.
Other add-ins are password protected. The current versions
of the add-ins all have the same password, ppp. We provide
this password, and open the add-ins to the public, for several
reasons. First when an error occurs, the user knowledgeable
in VBA may be able to correct it. A second reason is to allow
the user interested in programming in VBA to look at and use
sample code. The add-ins may not use the best coding practices,
but there is a great deal of code. It may be possible to use
parts of the code for other applications. Finally, we hope that
others will create add-ins for Operations Research. VBA is a
powerful language and Microsoft is constantly improving it.
We hope that there will be a community of persons providing
add-ins for all to use.
If you find and correct an error, improve the code or create
a new application, please notify the author so your work can
be made available to others.
The VBA Editor
Excel and the other
applications of Microsoft Office include a VBA Editor that
allows the user to view, create and change programs. To reach
the editor, open Excel, select Macro on the Tools menu
and select VBA Editor from the submenu. This takes you
to the editor. On the Mac, the F11 function key with
the Option key toggles between Excel and the editor.
Once in the editor, select Project Explorer from the View menu.
The Project Explorer window lists all the add-ins currently
installed. Click on the add-in of interest. If it is password
protected, enter the password. The source code and forms for
the add-in are contained in folders. Simply open a folder and
open the module containing the code. Return to Excel by using
the toggle key or selecting Excel from the View menu.
If an add-in is changed, you must save it by selecting Save on
the File menu. Before issuing the Save command,
be sure to have the cursor placed on a module belonging to
the add-in in the Project Explorer.
If you use or modify the add-ins, this author would be glad
to hear about it.