Dummy Data – How to use the Random Functions
Using collected or known data is the best when developing Excel models, but from time to time this may not be available when you are developing your model.
This post will look at some options for setting up Dummy Data using Excels Random functions.
Variability
Real data displays a range of variability, but this variability is generally within ranges or distributions of ranges of results.
All fields type can contain variability
ie: Country, State Names and Zip/Postal Codes, Maybe large lists but are fixed
Peoples Names, Maybe a large lists but are fixed by local rules
Ages, generally less than 80, never less than 0
Dates: Rarely before 1990 or 1900 in rare cases
Lists: are fixed
Numbers: generally random or conforming to a fixed distribution or known trend
Numbers: may include integers, decimals, negatives, extremely large numbers or all combinations
In generating random lists you will need to choose if you want random data, random data within constraints or random with a distribution. The choice is really yours and should in part be based on what the data is being used for and how accurately it needs to reflect reality.
Techniques
The techniques described below are all shown with a worked example in the attached Examples File or the Excel 2003 Example
Each example is annotated below like (Example 4.). ie: Refer to Example 4 in the above example files.
Dates
Setting up Random Dates is a simple process using the Date function.
=Randbetween(StartDate,EndDate)
Dates in a Range of Years
=Randbetween(Date(2000,1,1),Date(2011,12,31))
Will give a list of Random dates between 1 Jan 2000 and 31 Dec 2011 (Example 1.)
(Thanx Mike W)
Dates in a Month
=Date(2010, 6, Randbetween(1,30)
Will give a list of Random dates between 1 June 2010 and 30 June 2010 (Example 2.)
Don’t worry that the above formula (Example 1) can actually produce a 31 Feb 2005, the Date function will happily convert that to 3 March 2005 (Example 3.)
Dates within a Date Distribution
=DATE(2011,7,NORMINV(RAND(), 0,60))
Will give a list of Random dates between approximately 1 Jan 2010 and 31 Dec 2010, with a mean of July 1 and standard deviation of 2 Months (60days) (Example 4.)
Where NORMINV(RAND(), 0,60) will return values between -180 and +180, 99.7% of the time
Text Fields
Dependant on how many items in the list you require there are 3 techniques available
Choose
For small lists of less than 6 to 10 items you can use a simple Choose function (Example 5.)
=Choose(Randbetween(1,6),”Item 1″, “Item 2”, “Item 3”, “Item 4”, “Item 5”, “Item 6”)
VLookup
Using VLookup (Example 6.)
=Vlookup(Randbetween(1,List Length), List, 2)
Index
Using Index (Example 7.)
=Index(List, Randbetween(1, Counta(List) ))
Numbers
Small Random List of Numbers
Random from a small list of numbers (Example 8.)
=Choose(Randbetween(1,6), Numb 1, Numb 2, Numb 3, Numb 4, Numb 5, Numb 6 )
Note that the numbers:
- Don’t have to be in any order,
- Can be integers, negatives or contain decimals
- Can be repeated
eg: =Choose(Randbetween(1,6), 18, 21, -19, 36.4, 18, 24)
Random Integers
Return Integers between Start and Finish (Example 9.)
=Randbetween(Start, Finish)
=Randbetween(50, 100)
Will return an Integer between 50 and 100
Random Numbers
=Rand()
Will return a random number between 0 and 1
=Round(Rand()*100, 2)
Will Return Numbers between 0 and 100 with 2 Decimal places (Example 10.)
Random Numbers Based on a Distribution
=Norminv(Rand(), Mean, SD)
Will return a random number between 0 and 1 based on a distribution of Average = Mean and Standard Deviation = SD
=Norminv(Rand(), 50, 17)
Will return a random number between 0 and 100 based on a distribution of Average = 50 and Standard Deviation = 17, (Example 11.)
Random Numbers Fitting a Trend
If your distribution has to match a trend add a Random component to the Trends equation (Example 12.)
Y=mX+c
= rand() * X + rand()*5
= rand() * A2 + rand()*5
True/False
Choose
Use Choose and Randbetween (Example 13.)
=Choose(Randbetween(1,2), True, False)
If
Use If and Rand (Example 14.)
=If(Rand()<0.5, True, False)
Combination Text and Numbers
The above techniques can be combined to make lists of Alpha Numeric Data
Say your business has a fleet of vehicles (TR=Truck, VN=Van, CAR=Car)
=Choose(Randbetween(1,3),”TR”,”VN”,”CAR”) & Text(Randbetween(1,15),”0#”)
Will randomly choose 1 of “TR”,”VN”,”CAR” and add a random number between 1 and 15 to it format with a leading 0, eg: TR05, (Example 15.)
Other Sources of Data
Random Data
There are a number of web sites where Random Data is available.
http://www.fakenamegenerator.com/order.php
http://www.generatedata.com/#generator
http://www.melissadata.com/lookups/
Open Source Data
There are a number of web sites where Open Source Data is available.
http://www.readwriteweb.com/archives/where_to_find_open_data_on_the.php
Function Used:
Rand: Returns a random number between 0 and 1.
Randbetween: Returns a random Integer between lower and upper limits. Pre Excel 2007 Randbetween was only available through installation of the Analysis Toolpak (Thanx Luke).
Norminv: Returns the inverse of the normal cumulative distribution. That is it returns the X value from a Normal Distribution that has a know Mean and Standard Deviation where the a known cumulative percentage is supplied.
Choose: Choose an item from a list of up to 254 items.
Vlookup: Lookup the matching value from a list and return a data item from another column from the same location.
Index: Retrieve an items from a defined location within a range.
Text: Displays a number as Text with a defined format.
Other Uses of Random Functions
Of course the techniques shown here don’t have to be used for setting up Dummy Data.
One area where Random numbers is used is in Monte Carlo Simulation. This has been discussed at Chandoo.org at Data Tables and Monte-Carlo Simulations in Excel a Comprehensive Guide
Techniques
The techniques described above are all shown with a worked example in the attached Examples File or the Examples File 2003 ver
Limitations in Pre Excel 2007 versions
The Excel function, Randbetween, was only introduced in Excel 2007. As such the exaples above will only work in 2007/10.
However a simple alternative is available
Randbetween(Low, High) = Low + Int(Rand()*(High-Low))+1
Randbetween(90, 100) = 90 + Int(Rand()*10)+1
Examples using this approach are shown in the 2003 Version of the Examples files above.
How have you made Dummy Data or used the Random Functions?
How have you made Dummy Data or How have you used it ?
How have you used Random Numbers in your workbooks ?
Let us know in the comments below:
14 Responses to “How to Add your Macros to QAT or Excel toolbars?”
We have only just got excel 2007 so this is helping me navigate my way through the differences cheers.
For Macro's i always add a Command Button, rename it something obvious, change the colour of it and finally add the following to its View Code section.
Application.Run "MAcro1"
This way anyone opening the file knows what to do if i ever win the lottery and dont make it in 🙂
Hi,
Good article. But I have this problem.
1) Customized QAT with a macro. Macro name = MacroX
2) Runs OK from original location (e.g. C:\TestLoaction1\TestFile.xls)
3) Copy past file to new location (e.g. C:\TestLoaction2\TestFile.xls)
Menu button now fails:
Cannot run the macro "C:\TestLoaction1\TestFile.xls'!MacroX' The macro may not be available in this workbook...
Of course the code is there, and macros are enabled.
Could get it to work after deleting and recreating macro custom buttons. So have to re-assign macro to QAT button every time I move the file?
If I put a form button on he worksheet and assign the macro to that, it's location independent.
Any ideas?
Thanks
@Ron
What you have said is correct
Macros within a worksheet are stored within the worksheet and hence follow it.
Macros referenced by a button in the QAT or elsewhere are locaed in a file and if that file is moved the linkages don't follow.
The easiest way around this is to store all your macros in a location that doesn't move and is in fact reloaded everytime that Excel starts and that is called the Personal.xlsx/b file.
These are refered to several time at Chandoo.org or have a read of
http://www.rondebruin.nl/personal.htm
or
http://office.microsoft.com/en-us/excel-help/deploy-your-excel-macros-from-a-central-file-HA001087296.aspx
In Excel 2003 and prior versions, a button added to the Toolbar maintained a DYNAMIC link to the file (e.g. Personal.xlsb) holding the assigned macro, such that if the file was relocated for any reason (by using Excel's native Save As command rather than just moving it via Windows Explorer), the link between the button and the file was updated.
I expected the same to occur with Excel 2007+, but alas, Microsoft in their infinite wisdom have removed another feature useful to advanced users (just as they did by removing the ability to design your own buttons)!!
So having just done some reorganisation of my files, I now have to remove and recreate every friggin macro button on my QAT (I have lots) - what a pain in the proverbial!!
Hi Hui,
Thanks for the help, that's really useful.
1) The macros I'm adding are for one specific Excel application, so I really wanted the macros to follow the file
2) I didn't want to have to pass other files around too and have users installing those - either Personal.xlsx/b or as an Add-In.
3) I realise now that the QAT additions will appear for other Excel workbooks in which I don't want the macros available.
So, it looks like I need to keep it local, by using a button on the worksheet. Unless you can suggest any way of adding to menus just for a specific workbook.
Thanks again for your help. Great site, so I'll be signing up for the emails.
Ron
I know I'm a little late jumping on this post, but wondering if anyone knows how to add a UDF to the QAT? I've saved my UDF in my personal workbook, but it does not show up in my list when I choose Macros when customizing my QAT. Suggestions? Thanks!!
@Cheryl: UDFs cannot be accessed like Macros. You can use them from other macros or from worksheet cells as formulas...
@David: If you save your macros file and then install it as an add-in then it will be always available for you.
The instructions work great when you are creating a new file, and it is still open. I find that I can't access macros after I've saved a file as an xlam and closed it. When I reopen the xlam, either by browsing to it, or by having it set to open as an addin using Excel Options, the macros are no longer available in the macros list when I go to edit the QAT. Any way around that?
[...] Add this macro as a button to Quick Access Toolbar [...]
I need to create a button that will run a macro. Once you click the button it needs to open up a browser asking you to select a report/file. Once you select the file, it will run the macro on the selected file and then save it as a new report with a name and the current date. I created the macro to sort/modify the report but I do not know how to do what I mentioned above. I hope this makes sense.
I'm having trouble adding a macro to the QAT. I've done everything up to step 5 but my macro isn't showing up. What am I doing wrong?
[...] Add Macros to Quick Access Toolbar (works in Excel 2003 & above) [...]
Hi,
Thank you for the explanation. Very useful for a recent switcher from office 2003 to office 2010.
My follow-up question is: in Excel (or ppt) 2010, can you customize the macro button that you put in the QAT?
In office 2003, once you chose the custom button for your Macro, you could then edit pixel by pixel the said button.
For instance, I've created 2 Macros in PPT that are converting all my slides to either English or French language, so I'd like one button to show EN and the other FR... that would be more meaningful that any of the possible "custom" office 2010 buttons
I read all the post and one important aspect to the QAT was never mentioned. That is, you have a macro driven worksheet that you want to share with other. You have customized the QAT with two icons to run the macros (VBA programs in reality). However, when the others receive the workbook, the icons are no where to be found. It's my understanding those "customized buttons" have been saved to an outside file, Excel.qat. QUESTION: Could one simply attach that file to your email, along with the worksheet, and tell the recipients to copy that file to correct location on their computer - C:\Users\\AppData\Local\Microsoft\Office|\
Would the customize macro buttons then appear in the worksheet and, more importantly, work? Thanks for your thoughtfulness and thanks for well written instructions Chandoo!
MortW