Public Function randomdouble(lowerbound As Double, upperbound As Double) As Double On Error Resume Next

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1 Table of Contents Introduction...1 Using VBA Functions...1 Accessing Visual Basic in Excel...2 Some Example Functions...3 Random Numbers...4 RandomDouble...4 randomint...4 Using the random numbers...5 Ranges of Values...6 Integer Ranges... 6 Char Ranges...6 Date Range...7 Sets...10 Excel Ranges as Sets...11 Shriek Functionality...12 Calling Macros...14 Introduction This document presents some ways in which MS Excel, combined with a little simple VBA (Visual Basic for Applications) can be helpful when generating test data. Using VBA Functions In the Visual Basic editor it is possible to create functions which can be used as though they were normal excel commands e.g. With the following code in Visual Basic in the spreadsheet: Public Function randomdouble(lowerbound As Double, upperbound As Double) As Double On Error Resume Next If upperbound < lowerbound Then randomdouble = (lowerbound - upperbound) * Rnd + upperbound Else randomdouble = (upperbound - lowerbound) * Rnd + lowerbound End If End Function Public Function daterange(fromdate As Variant, todate As Variant, Optional tformat As String = "dddddd ttttt") As String Dim fdate As Date, tdate As Date cast the variants fdate = fromdate tdate = todate Dim lcount As Double, mcount As Double convert the dates to doubles lcount = fdate mcount = tdate set the return date formatted to the correct style daterange = Format(randomDouble(lCount, mcount), tformat) End Function We can create random dates in a range by typing a daterange command into a cell, since there is no MS Excel function called daterange our custom VBA function will be called instead:

2 =daterange( 12/4/76, 14/6/89 ) The quotes are necessary otherwise, MS Excel will interpret the date as being = 12 dividedby 4 dividedby 76 The Cell will display a random date between 12/4/1976 and 14/6/1989. As shown below. Using the normal MS Excel autofill process, we can create a whole series of random dates in this range. Grab the corner of the cell and drag down. Values will be automatically filled in to the cells. Accessing Visual Basic in Excel In the example datagen.xls file, you can view the visual basic code by using the Visual Basic editor accessible from the Tools\Macro menu hierarchy. All code is either in the Workbook, or the Modules section of the project hierarchy (module1).

3 Some Example Functions The following sections will describe some example VBA functions which might be of use for generating test data.

4 Random Numbers Starting with the random number functions as these are used by other functions which generate ranges. randomdouble randomint =randomdouble(x,y) returns a random double between two given double values X and Y e.g. =randomdouble(4.0,10.0) generate a random integer between 4.0 and 10.0, e.g =randomint(x,y) returns a random integer between two given integer values X and Y e.g. =randomint(100,40) generate a random integer between 100 and 40, e.g. 67 Both functions have checks in place so that no matter what order the paramaters are e.g (lowervalue,highervalue) or (highervalue,lowervalue) the functions still return a value within the range. RandomDouble Uses the MS Excel Rnd command which returns a double between 0 and 1. The code fragment (lowerbound upperbound + 1) * Rnd + upperbound was in the MS Excel help file and is a standard way in Excel of generating random numbers between a range. Here we have encapsulated it in a function because we will reuse it often, and we are making it resilient to the parameter order. I have also removed the +1 The MS Excel help file is very good. Use it regularly and explore it to see what commands are built in to Excel. Press F1 in Excel to access the help. randomint randomint is very similar to the randomdouble function.

5 Using the random numbers Both randomint and randomdouble can be used directly in MS Excel cells to return a random number between two upper and lower boundaries: =randomint(3.10) =randomint(10,3) =randomdouble(3,10) =randomdouble(10,3)

6 Ranges of Values A range in MS Excel has a very specific meaning, but here we are talking about a set of values between two other values. The use of Excel ranges to generate test data will be discussed later <section to be written>. Integer Ranges <examples> <repeatedranges> Char Ranges

7 And we can repeat the ranges to make strings Date Range DateRange will return a formatted date randomly chosen from between two supplied dates.

8 the tformat paramater can be General Date Long Date Medium Date Short Date Long Time Medium Time Short Time using Windows settings using Windows long date format. using the medium date format appropriate according to Windows using Windows short date format. using Windows long time format time in 12-hour format with hours and minutes and AM/PM time in 24-hour format Or made up from : Local Time separator / Local Date Separator c d dd ddd dddd ddddd dddddd aaaa w ww m mm mmm mmmm oooo q y yy yyyy h Display as ddddd ttttt day (as a number) without a leading zero day (as a number) with a leading zero day as an abbreviation Full name of day Windows Short Date format Windows Long Date format Localised dddd day of the week as a number week of the year as a number month (as a number) without a leading zero. Or acts as a minute value if used after h or hh month (as a number) with a leading zero. Or acts as a minute (see above) month as an abbreviation month as a full month name Localised version of mmmm quarter of the year as a number day of the year as a number year as a 2-digit number year as a 4-digit number hour as a number without leading zeros Hh hour as a number with leading zeros.

9 N Nn S Ss t t t t t AM/PM am/pm A/P a/p AMPM minute as a number without leading zeros minute as a number with leading zeros second as a number without leading zeros second as a number with leading zeros time as defined by Windows use 12-hour clock and uppercase AM or PM use 12-hour clock and lowercase AM or PM use 12-hour clock and uppercase A or P use 12-hour clock and lowercase A or P use 12-hour clock and AM or PM defined by Windows Settings

10 Sets The setval function returns one of the values in the set at random. Autofill can then be used to quickly populate a column with values in a set.

11 Excel Ranges as Sets To Create a Range, highlight an area, then create a named range, then type in the name. We can then programatically get a random value from that range using =valuefromexcelrange("bee3)

12 Shriek Functionality The macros "Create New Data Sheet" will run a macro across the current worksheet and create a new workbook with the formulas copied as values and any "!*" cells expanded e.g. The values above are the results of formulas: "10" above is a =randomint(3,10) and "08 February :50:44" is actually =daterange("12/4/1976", "14/6/1989") The formulas would be recalculated and copied as actual values and would become: where the row after!*23 was repeated 23 times. The "Create New Sheets from! Sheets" will do the same for all sheets named!<something> in the spreadsheet. e.g

13 In our example sheet we have 2!sheets:!data1!data2 Running the macro "Create New Sheets from! Sheets" will create a new workbook with two extra sheets: data2 is: data1 is: The 3 code subroutines which do this are: copysheettosheet createsheetfromactivesheet createsheetfromshrieksheets The code has minimal commenting but should be understandable.

14 Calling Macros A custom set of menu commands were created in the tools menu automatically by using some VBA code. In the workbook we use the open event to create the menu and get rid of the menu in the BeforeClose event Full code for these events follows (although it is easily viewable in side the Excel VBA editor):

15 Private Sub Workbook_Open() Dim CmdBar As CommandBar : Dim CmdBarMenu As CommandBarControl Dim CmdBarMenuItem As CommandBarControl Point to the Worksheet Menu Bar Set CmdBar = Application.CommandBars("Worksheet Menu Bar") Point to the Tools menu on the menu bar Set CmdBarMenu = CmdBar.Controls("Tools") Add a new menu item to the Tools menu Set CmdBarMenuItem = CmdBarMenu.Controls.Add Set the properties for the new control With CmdBarMenuItem.Caption = "========Test Data Addin=========".OnAction = "".Tag = "_CD_TestDataInSitu_v1_0".Enabled = False End With Set CmdBarMenuItem = CmdBarMenu.Controls.Add Set the properties for the new control With CmdBarMenuItem.Caption = "Create New Data Sheet".OnAction = "" & ThisWorkbook.Name & "!createsheetfromactivesheet".tag = "_CD_TestDataInSitu_v1_0" End With Set CmdBarMenuItem = CmdBarMenu.Controls.Add Set the properties for the new control With CmdBarMenuItem.Caption = "Create New Sheets from! Sheets".OnAction = "" & ThisWorkbook.Name & "!createsheetfromshrieksheets".tag = "_CD_TestDataInSitu_v1_0" End With Set CmdBarMenuItem = CmdBarMenu.Controls.Add Set the properties for the new control With CmdBarMenuItem.Caption = "Information About AddIn".OnAction = "" & ThisWorkbook.Name & "!helpnow".tag = "_CD_TestDataInSitu_v1_0" End With Set CmdBarMenuItem = CmdBarMenu.Controls.Add Set the properties for the new control With CmdBarMenuItem.Caption = "============================".OnAction = "".Tag = "_CD_TestDataInSitu_v1_0".Enabled = False End With End Sub Private Sub Workbook_BeforeClose(Cancel As Boolean) On Error Resume Next Dim CmdBar As CommandBar : Dim CmdBarMenu As CommandBarControl : Dim CmdBarMenuItem As CommandBarControl Set CmdBar = Application.CommandBars("Worksheet Menu Bar") Set CmdBarMenu = CmdBar.Controls("Tools") Set CmdCtrl = Application.CommandBars.FindControl(Tag:="_CD_TestDataInSitu_v1_0") While Not CmdCtrl Is Nothing CmdCtrl.Delete Set CmdCtrl = Application.CommandBars.FindControl _ (Tag:="_CD_TestDataInSitu_v1_0") Wend End Sub