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:
25 Responses to “Display Alerts in Dashboards to Grab User Attention [Quick Tip]”
I prefer the red,grey,light grey,black icon set. I've also used in-cell pie charts from Fabrice's Sparklines for Excel as an alert which could also provide another piece of information.
I prefer the red,grey,light grey,black icon set. I've also used in-cell pie charts from Fabrice's Sparklines for Excel as an alert which can also provide another piece of information.
For Excel 2007, your formula should do the same as the Excel 2003 version, so that non-alert rows are blank - if they are 0, the unnecessary green icon will show
Hi Chandoo,
Nice Post !! just to add something for EXL 2003, we can also 4 Ifs and link to the alert data
For Ex: If we have alert data in Cell A2 and want to split in 4 orders namely <25%, 25-50%, 50-75% and 75%< then we can following formula and put fonts as you have suggested :
=IF(A2<0.25,CHAR(153),IF(A2<=0.5,CHAR(155),IF(A2=0.76,CHAR(152)))))
And then using Conditional Formating we can dashboard reflected on different COLOURS as per their respective alert.
Best Regards
Rohit1409
Hi Chandoo,
Nice Post !!! just to add something for EXL 2003, we can also 4 Ifs and link to the alert data
For Ex: If we have alert data in Cell A2 and want to split in 4 orders namely <25%, 25-50%, 50-75% and 75%< then we can following formula and put fonts as you have suggested :
=IF(A2<0.25,CHAR(153),IF(A2<=0.5,CHAR(155),IF(A2=0.76,CHAR(152)))))
And then using Conditional Formating we can dashboard reflected on different COLOURS as per their respective alert.
Best Regards
Rohit1409
The Complete formula [Don't Know how it got cut ]
=IF(A2<0.25,CHAR(153),IF(A2<=0.5,CHAR(155),IF(A2=0.76,CHAR(152)))))
PS : Use in single line [I have split it to avoid cuts 😉 ]
Hi Chandoo..
why it is not displaying the complete formula..
anyways here is the balance
"=IF(A2<0.25,CHAR(153), IF(A2<=0.5,CHAR(155), IF(A2=0.76,CHAR(152)))))"
@Rohit... your formulas are fine. Just that the width of comment area is fixed and hence my website is cropping it at 640pixels. I just edited your formula and added few white spaces so that it wraps nicely.
Very good idea btw.. kudos!
Hi,
Maybe just go for 'bold' ; 'underline' or 'italic' to draw the users attention? Those methods (if those can be called methods) are used cross media type (books, journals, blogs, billboards, ...) to guide the readers eye to valuable information.
Just a basic thought
@Tom.. good idea..
[...] has a very nice writeup on how to add such alerts to dashboard sheets. Possibly related posts: (automatically generated)Divide your data set into workbooksHow to enforce [...]
Hi Chandoo,
You certainly grabbed my attention! although I wasn't sure what my brother (Suresh) and cousin (Shyam) were doing right, and I was doing wrong? 😉
I love your blog btw - Many thanks for all your hard work in unravelling the secrets and mysteries of Excel!
Best regards
Ramesh
I thought I saw an advertisment for a book about learning excel called excel himalaya or something. It cost about 35.00 us money but seemed to have the things I need to have my admin assistant to start to use. I was hoping to start with this book and then send her to school if she shows some interest and aptitude. Any help on this would be appreciated. Thanks
Great web site and information!!!!
@Jeff... checkout http://chandoo.org/wp/2010/08/25/excel-everest-review/
thanks, your website is awesome!
[...] Alerts to highlight focus areas [...]
[...] There are lots of numbers in this dashboard. I would suggest adding few more visualizations like showing indicators or applying conditional formatting or replacing a table with a chart. This would reduce the [...]
[...] is the same technique as alert icons in dashboard. Just that I also showed green [...]
[...] is the same technique as alert icons in dashboard. Just that I also showed green [...]
Hi Chandoo
Firstly thanks for all the cool tips on how to use Excel better.
I am new to the site and have a question which you may be able to assist with but dont know if these comment boxes are the best way of asking ?
I am looking at assets and trying to calculate the depreciation total by taking a year (say 2010) adding the expected life of the asset (say 10 years) then comparing that to a future date (say 2015) using an IF statement. The calculation in normal is - IF((year in col B (2010) plus 10years)>year 2015, add a years depreciation, otherwise leave blank). The converted date value does not appear able to add 10 years in order to compare it to 2015. Am I missing something ?
I use the “IF” Statement in conjunction with Conditional Formatting in MS Excel to give verbiage to alert one of a required action, dependant on a review date. This makes a visual stimulus, plus it clues one as to what the conditional format is trying to warn you about and what follow-up actions are required.
Wow, I'm really impressed with dashboards. I had no idea this stuff was even possible with excel. I'd like to offer an interactive dashboard to my customers, showing analytics of their data. I have a .pdf file with the datapoints. I'd like them to enter the data on my website, and be able to see their data. Is something like that possible.
Hi Chandoo,
I've recently purchased the package for both templates.
In the portfolio dashboard,under the calculations worksheet, I'm attempting to change the date range in the gantt chart to show only the range of the project that starts in late 2013. How do I do this?
Thanks
Adam
[...] is the same technique as alert icons in dashboard. Just that I also showed green [...]
Hi Chandoo,
I'm new at Excel Dashboard and found your blog really useful and helpful! It's very nice of you that you dedicate your time to do this.
Could you please explain how can I use Alerts based on dates on a Dashboar?
For example, if a target date is coming closer to the actual date, the alert is yellow or red.
I'd really appreciate some help!
Thank you
Where can I download the file Excel of Averall Statistics ???
Thanks a lot.