Page 24 - Excel for Scientists and Engineers: Numerical Methods

Chapter 1

Introducing

Visual Basic for Applications

In addition to Excel's extensive list of worksheet functions and array of
calculation tools for scientific and engineering calculations, Excel contains a
programming language that allows users to create procedures, sometimes
referred to as macros, that can perform even more advanced calculations or that
can automate repetitive calculations.
Excel's first programming language, Excel 4 Macro Language (XLM) was
introduced with version 4 of Excel. It was a rather cumbersome language, but it
did provide most of the capabilities of a programming language, such as looping,
branching and so on. This first programming language was quickly superseded
by Excel's current programming language, Visual Basic for Applications,
introduced with version 5 of Excel. Visual Basic for Applications, or VBA, is a
"dialect" of Microsoft's Visual Basic programming language, a dialect that has
keywords to allow the programmer to work with Excel's workbooks, worksheets,
cells, charts, etc. At the same time, Microsoft introduced a version of Visual
Basic for Word; it was called WordBasic and had keywords for characters,
paragraphs, line breaks, etc. But even at the beginning, Microsoft's stated
intention was to have one version of Visual Basic that could work with all its
applications: Excel, Word, Access and PowerPoint. Each version of Microsoft
Office has moved closer to this goal.

The Visual Basic Editor
To create VBA code, or to examine existing code, you will need to use the
Visual Basic Editor. To access the Visual Basic Editor, choose Macro from the
Tools menu and then Visual Basic Editor from the submenu.
The Visual Basic Editor screen usually contains three important windows:
the Project Explorer window, the Properties window and the Code window, as
shown in Figure 1-1. (What you see may not look exactly like this.)
The Code window displays the active module sheet; each module sheet can
contain one or several VBA procedures. If the workbook you are using does not

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