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:
28 Responses to “Pimp your comment boxes [because it is Friday]”
This borders on Excel soft-cell...er, soft-core...porn. My favorite kind.
Wow, that is pimp-TASTIC! I have a question, as a VBA n00b: additional comment boxes stay plain unless I "run" the macro. Is there a way to change all comments, going-forward?
hi Chandoo, well, I like the macro approach. For those who don't like it, there is another way: just add the "draw" toolbar to the shapes toolbar (via Custom etc), click on "edit comment", click on the auto-shape and then choose "draw" drop-down, --> modify auto-shape --> then you even can have a heart or a banner (I like the horizontal banner in in purple :-)) . in excel 2007, you have to add this custom menu that you choose via Excel Options --> Custom --> it is called "change/ modify auto-shape"!!!
best,
@Chandoo. Great Post 🙂
@Tim : the way the macro is coded, it must be run very time.
@Community: If someone has an idea to perform it when opening an existing excel, it should be nice.
@Community: if someone has some code to revamp the commentboxes on all sheets, please share it. 🙂
@Microsoft Excel-progammers: some pimpoptions for the commentboxes should be great.
Cheerio
Tom
For the auto run, please add the codes in workbook:
Private Sub Workbook_SheetActivate(ByVal Sh As Object)
Call Comments_Tom
End Sub
Wow, that was a lot of fun... Thanks Tom!
@Jeff... Now, 5000 people know about your favorite porn... 😛
@Tim ... you can write an event to handle the new comments. I wouldnt recommend it as it is really painful. another option is to use the macro suggested by Yukikomi. It will update comments everytime you activate the sheet.
@laguerriere: very cool 🙂
@Chandoo ... Thanks! This is good stuff. I combined your tip with a tip from Mark O'Brien, then assigned it to a button on Excel 2010's Quick Access Toolbar, to format comments AS I add them. I also like how Mark's code saves me the trouble of backspacing my name out of new comments:
Sub AppendToExistingComment()
'Source: Mark O'Brien at http://www.mrexcel.com/forum/showthread.php?t=57296
Dim oRange As Range
Dim oComment As Comment
Dim sText As String
'Use object variable to hold range.
Set oRange = ActiveCell
'Use object variable for comment
Set oComment = oRange.Comment
'text to be added to the comment box
sText = InputBox("Type text to be added:", "APPEND TO COMMENT TEXT")
If Len(sText) = 0 Then End
'If Active Cell has a comment then append new text to the end of the comment text
If Not oComment Is Nothing Then
sText = oComment.Text & vbNewLine & sText
oRange.Comment.Delete
End If
'Add a comment with the contents of sText
oRange.AddComment sText
DoEvents
Comments_Tom
End Sub
Thank you very much for the code, it seems to be working for the most part; I am having a problem however. Once the routine makes the corrections to the comment, the comment becomes invisible. By invisible, I mean that when I highlight my mouse over it, nothing appears. However, when I right click the cell and click 'edit comment' then the comment becomes visible and I enter edit mode. Upon clicking out of the comment, it simply vanishes again. I've tried to fix this problem by adding a .shape.visible = msoTrue but then every comment is always visible. o_O please advise...
Thank you,
Nick
@Nick- That is because the font color of the comment is white and when you select the color of selection is also white hence you can not see anything. Try to change the color code in the routine to something else. would work
Thanks for that! The code works perfectly!
[...] look at Format Excel Comment Boxes using VBA Macros | Chandoo.org - Learn Microsoft Excel Online [...]
@ Chandoo - code works great and the comments look super cool. But I have ran into a small issue. In the comments, I am inserting pictures. When I run the macro, for all comments which already have pictures; pictures are deleted. Pls help me retain the pics in comments.
[…] posted some code one of his readers submitted, it "pimps" your comment boxes from those boring black-text-on-yellow rectangles to something more professional and eye-pleasing. […]
love in it
Hi Tom,
This looks really excellent. I am however relatively new to macros / VBA codes so having copy pasted your code in the Developer mode of an Excel file, what are the next steps to use them? Can you please help? Just to recap, I opened a blank Excel workbook, clicked on Developer, copy pasted the comments code and saved the file to the desktop.
Now how do I go about using it to add comments to an existing file? My apologies for asking a question which may be basic to you great geniuses, but I am not there yet and aspire to get there.
Many thanks for helping me with next steps that I need to take so that I can now use the code.
Best Wishes
Deepak Dave, CMA, MBA, PMP
Senior Management Consultant
Dear Dave,
The best thing to do is to copy the macro in the personal.xls(x) file. The personal excel file will always be launched when you open excel so you can use it with every excelworkbook.
Read all about it on the page of Microsoft.
https://support.office.com/en-us/article/Copy-your-macros-to-a-Personal-Macro-Workbook-aa439b90-f836-4381-97f0-6e4c3f5ee566
Once you have the macro in the personal, you can 'call' the macro by the keyboardcombination 'alt+f8' and klik on the macroname.
Hope this clarifies the 'how to'. Good luck with your first steps in the wonderfull world of macro's.
Tom
Hi Tom,
Many thanks. I will try that out. Learning is fun and learning this stuff is even more amazing.
Best Wishes
Deepak Dave
There is a line 'Dim LArea As Long' which does not appear to be used. Have I missed something?
Dear Gary,
Correct the 'Dim LArea As Long' is indeed not relevant and can be deleted.
Tom
Excellent hack!
For some reason when I opened my file after using LibreOffice Calc, all comment boxes had changed to some arrow shape.
So this macro helped me from manually changing more than 5000 comments in a worksheet, or having to install some Excel extension.
I used it with the following attributes to get back old style comments:
It helped me from manually changing more than 5000 comments in a worksheet, or having to install some Excel extension.
.Shape.AutoShapeType = msoShapeRectangle
.Shape.TextFrame.Characters.Font.Name = "Calibri"
.Shape.TextFrame.Characters.Font.Size = 10
.Shape.TextFrame.AutoMargins = True
.Shape.TextFrame.AutoSize = True
Thanks a lot!
This was helpful, thank you
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the articles is really great : D. Good job, cheers
Is there code to add to this that will format a particular part of the comment (i.e. make the last sentence in the comment bold and in italics)?
This is fantastic!
How would I add auto-sizing to it?
I tried adding this:
.Shape.AutoSize = True but it gives me an error and as a novice at VBA I can't figure it out.
.Shape.TextFrame.AutoSize = True
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How should the code be changed in order to tun once for all worksheets in a workbook?