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:
54 Responses
Hi Chandoo,
This is awesome *****
Found 6, just one remaining, and I think it should be in sheet2, as I found 1 in each sheet but didn’t found anything in sheet2 (till yet, I am keep looking).
Very cleaver and amazing work, enjoyed a lot…
Thanks Chandoo for this beautiful work.
Wish you have great time at Hyderabad.
Regards,
Khalid
go to AB201 on Sheet2, you will see Panda there !!!
Press F2 in Cell A1 and then read the actual text !!
In Sheet 2 go to Cell AB201. You will find one.
There is one on first sheet, if you press F5 (goto), the word PANDA can be seen there.
Oh I found the last one, (custom format hmm)
Truly Amazing and the beauty of this forum.
You are an Artist Chandoo.
Hi Chandoo,
Wow, you really have magical skills. I am in office and this sheet ate up an hour of my time….didn’t expect that.
I could find 5 of the 7 pandas. Didn’t know one could hide so much data in innocent looking excel sheets.
Thanks!
-Ranjith
yeah! found all 7 panda, time to go to china.
This was very fun and challenging, thanks for posting! I found all of them (well, Sheet1 was tricky, it seems you’re supposed to find the cell and type it in yourself?). Wasn’t sure if it was cool to post the answers here or not, though. Guess I’ll post SPOILER ALERTS so you can skip the rest of the message if you don’t want to see what I came up with.
SPOILER! SPOILER! SPOILER!
My answers appear below.
Sheet1: type PANDA in cell PAN3489
Sheet2: cell AB201
Sheet3: cell J8 (Picture1)
Sheet4: cell H9
Sheet5: expand Chart1
Sheet6: formula = “=MID(ADDRESS(9,2^3*23*59,4),1,3)&BIN2HEX(11011010)”
Sheet7: named range (A1:I18)
Wookie – I would love to get a walkthrough of HOW you figured out sheet 1 and a bit of a formula walkthrough for Sheet 6.
Basically, I don’t know how I could have found that particular cell input message on Sheet 1.
And I have no clue about the BIN2HEX part of the formula…before your hint I was able to get the output to read AN9DA. The change to MID and the addition of that ‘,1’ changed it to PANDA…
Hi Rachel,
To get to the cell in sheet 1 you can press: ctrl G. Then special and then data validation: all. This is also the way to find panda in sheet 7 😉
I agree, this was a fun way to test your ability to navigate through the functionality of Excel! And since you already posted the SPOILER ALERT warning, I should be safe posting a reply to your comment with some solutions of my own… 🙂
I found all the same solutions you did with a few minor changes:
Sheet1: If you notice, cell PAN3489 has Custom formatting. You don’t have to type “PANDA”, just the number 1.
Sheet6: The MID function works as you described, but you can also simply change the RIGHT function to the LEFT function without having to add in the start and end positions for MID.
Sheet7: Yes, the range name for these cells is called PANDA, but you don’t see the actual word in the sheet unless you change the Zoom setting to 39% or less (hence the clue “Z” 39%).
Thanks again for a great post, Chandoo!!
I must admit sheet 7 defeated me, but I have some corrections
Sheet 1 – you type =LEFT(ADDRESS(ROW(),COLUMN(),2),3)&DEC2HEX(ROW())
in PAN3489 to get “PANDA1”. As it is the first panda. I think panda1 is appropriate, but maybe
=LEFT(ADDRESS(ROW(),COLUMN(),2),3)&LEFT(DEC2HEX(ROW()),2)
is better, because it leaves you with “PANDA”
Sheet 6 – I corrected to
=LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
Picky I know, but who uses mid when a right or a left will do?
I know; that was weird. I did try using a LEFT formula, but I kept getting the $ prefix from the cell address. So I tried a couple of variations using MID and it gave me the result I needed. This is actually the first time I’ve ever tried using a MID formula starting at the first character, but I wasn’t trying to spend a lot of time on it, so I went with what worked.
Sheet1: Type 1 in PAN3489
Sheet6: =LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
Slight change…
For sheet 1 goto PAN3489 and type in 1. The word PANDA appears.
Love it!
Sheet 6 was my favorite. How many people still know what binary, hex and octal are? :o)
—–Spoilers———
Alternate Solutions
1) Type “1” (not the quotes) in PAN3489 and Excel will turn “1” into “PANDA”
6) The formula Wookie lists also works with LEFT in place of MID
Lot of fun. Solve time ~20 mins.
@ Rob
How this 1 turns to PANDA .. means How this is done by excel any formula or something in VBA
Also how to reach cell PAN3489 .. there are no clues given on sheet 1
You reach PAN3489 by pressing Ctrl + End to bring you to the last used cell in Sheet 1
@ Navdeep I found PAN3489 by going to “Formulas” and then “Name Manager” and saw there was a field called “Clue1” listed in the Name Manger that references 3489. Finding PAN as the column index was just a bit of a lucky guess through trial and error. Then a note in cell PAN3489 when you navigate there says to try “typing something.” I tried scrolling through the Format Cells menu to see if the text typed in the cell needed to be formatted a certain way, and noticed that “1= Panda” was listed in the custom text menu and tried it. A bit brute force, but I think the desired text entry.
Clever!
The Data Validation one took me a bit. Had to resort to brute force.
Thanks for the fun!
Awesome! Found 7 pandas in 20 minutes)))
Sheets 1 and 6 were the best!
Thanks!
Sheet 1: The answer is not type in Panda. Type 1. There’s a special formatting that replaces 1 with Panda.
Sheet 6: Just replace right with left, don’t worry about changing the numbers.
Sheet 7: I found the named range, but don’t know what the Z 39% means. Thoughts?
when you changed the zoom level to 39% or below, you will see the name of namedrange (if any)
WOW! I’ve just found the secret eighth PANDA!
Truly awesome!!!
Am I the first one who figured that out, guys?
Btw, thanks for the puzzle!
Found them all – very inventive. Had to think outside the “box”. Great fun!
It was truly a artists work
chandoo you are grate
all sheets are deigned different from each other
@Wookiee: you have a good for others by posting the answers, Thank you too
it is fun and great invent
Guys I Got 8 PANDA in the workbook… 🙂
[Look Chandoo has against played great trick by reserving one more ester egg, but we are also fan of none other than Chandoo, who can get hold of hidden 8th (untold) ester egg]
Here is the full list:
1) Sheet1: Type 1 in Cell PAN3489
2) Sheet2: Goto Cell AB201
3) Sheet3: Check the picture located above cell J8
4) Sheet4: Goto Cell H8
5) Sheet5: Cells, viz., A4, A10, A16, A21, A29 have all alphabets of PANDA
6) Sheet5: Resize the chart to see PANDA
7) Sheet6: Correct the formula as LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
8) Sheet7: Range A1:I18 is named as PANDA
1) Sheet1: Type 1 in Cell PAN3489
2) Sheet2: Goto Cell AB201
3) Sheet3: Check the picture in the cell J8
4) Sheet4: Goto Cell H9
5) Sheet5: Resize the chart to see PANDA
6) Sheet6: Correct the formula as LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
7) Sheet7: Range A1:I18 is named as PANDA
Actually, for sheet7, if you set the zoom to 39% or less, you will see the word PANDA. Yet another PANDA! 🙂
Hi,
i want to know how to manage bill wise manage vendor invoice and payment in excel please suggest.
Thanks,
Ram
Hi Chandoo!
You rock with these amazing skills!
Sheet 1: ??
Sheet 2: ??
Sheet 3: Cell J8
Sheet 4: Cell H9
Sheet 5: A4, A10, A16, A21, A29
Sheet 6: B2
Sheet 7: ???
Sheet1 F5
Sheet2 AB201
Sheet3 Picture1
Sheet4 H9
Sheet5 Chart
Sheet7 Zoom to 30%
I love this time of year and look forward to Chandoo’s egg hunts. Whilst I got all the pandas, I do not understand how sheet 7 works; Where is the source data and why does it only work when zoomed out to 39% or more?
@Leon-K
When you change the zoom level to be less than 40% Excel shows the Ranges which have Names applied to them
Ha ha, that’s fantastic. Thanks Hui. @Chandoo, thanks for yet another method to decrypt worksheets in order to re-build or explain them better to clients.
These were fantastic and kept me intrigued until I could finish them. (Had to look here for help with Sheet1!) Definitely learning a lot about some new formulas. Awesome, Chandoo!
Ok, just saw the notes on the Zoom 39% on Sheet 7. Can someone explain what’s happening here and why PANDA shows up at that level?
@Bryan
When you change the zoom level to be less than 40% Excel shows the Ranges which have Names applied to them
Wow, great exercise.
Tried and solved 5 out of seven and other two solved incorrectly (1 & 6).
Thanks 🙂
Hi Chandoo,
Gr8 …had fun in searching it. I got 5 out of 7.
You are brilliant.
Found all except in sheet6 as not able to understand formula.
thanks
Raja Aurongzeb
Hi,
I am not able to find 1st Panda, which is on Sheet1. Rest all I have found.
Wonderful Chandooji… you are brilliant.
Wow.. Awesome set of puzzles Chandoo!!
Am now trying to figure out how sheet 7 was prepared.. 39% Zoom setting logic.. Can someone help me with a hint?
Thanks!
Looks like this is an XL feature.. Zooming out the worksheets below 40% level, by default displays all named ranges (more than 2 cells)! Had not come across this till date..
Great works! Was having FUN in finding the pandas. Thanks.
btw, I used one basic function (Find, CTRL+F) to find 2 pandas. Simply Find “Panda” within “Workbook”… To my surprise, seems no one mentioned that in the process.
On other other hand, Selection and Visibility Pane is a handy tool to see if there is “extra” shapes for locating pandas hidden in chart/picture.
Had fun doing this, Found 5 and the rest I saw clues on here 🙂
I really enjoyed when finding the pandas.And also I am so surprised.Very Nice thought and Excellent.
This was fun! Thanks!
Nice and fun post. Thanks, Chandoo!