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:
23 Responses to “Displaying Text Values in Pivot Tables without VBA”
Its possible to display up to 4 text values.
Have a look at the screen shot of an example that I had posted way back at the EHA and figure out how its done !
http://tinypic.com/r/muzywk/6
With Excel 2010 you can use Conditional Formatting to apply custom number formats which can display text. (In older versions you can only modify text color and cell background color, but not number formats.) Using CF allows for an even larger number of different display values.
[...] Display text values in Pivot Tables without VBA [...]
Hey,
Thanks, this helps. But how do you do it for multiple values where there is a huge amount of non repeating text?
@Soumya
The only way to do more than 4 values is to make the Pivot Table manually with formulas, of course then it isn't a Pivot table
You can of course do it with VBA
You may want to have a look at this description of how to do it here: http://www.clearlyandsimply.com/clearly_and_simply/2011/06/emulate-excel-pivot-tables-with-texts-in-the-value-area-using-vba.html
@Soumya
The only way to do more than 4 values is to make the Pivot Table manually with formulas, of course then it isn’t a Pivot table
You can of course do it with VBA
You may want to have a look at this description of how to do it here: http://www.clearlyandsimply.com/clearly_and_simply/2011/06/emulate-excel-pivot-tables-with-texts-in-the-value-area-using-vba.html
[...] Pivot Tables take tables of data and allow the user to summarise and consolidate the data at the same time. This is a great and very fast method of analysis but is restricted to handling mathematical functions on the value field resulting in numerical summaries. – read more [...]
[…] Read more here: Displaying Text Values in Pivot Tables without VBA […]
There is a very good way actually for handling text inside values area.
First you create a special column on the very left side and call it ID, and put unique ID (numbers only), and then create a pivot table with:
Row Labels and Column labels as you like, and in the Values labels use the unique ID number.
Move the unique ID number (copy paste) somewhere to the right and use vlookup to load the data you need using the ID as reference.
It is a bit longer way but for me it works perfectly to combine values as you like in any moment.
hope helps.
Regards,
Jon
Thank you! I finally understand pivot tables thanks to your clear, concise explanations and examples.
Good Day. This is exactly what i have been looking for. However when i try it on my pivot table or even when i try to recreate this exercise using the sample worksheet, i get this error:
"Microsoft Excel cannot use the number format you typed. Try using one of the built-in number formats."
Same thing here, Excel quite did not like the format in my PowerPivot. Any clues as to what may be going on? Thanks.
I have the same thing happening on my end. I'm running a normal pivot table on a .xlsm file.
@Danzi
What format did you use?
can you post the file ?
pls. help in table there is name, pan. amount. i have to make pivot table for example
NAME PAN AMOUNT
MR.X AAAAC1254T 500.00
MR.Y AAABR1258C
MR.A CFVDE2458T
MR.Z AAVCR12548C
MR.X AAAAC1254T
MR.Z AADCD245T
pls. help in table there is name, pan. amount. i have to make pivot table for example
NAME PAN AMOUNT
MR.X AAAAC1254T 500.00
MR.Y AAABR1258C 1000
MR.A CFVDE2458T 2000
MR.Z AAVCR12548C 5451
MR.X AAAAC1254T 45564
MR.Z AADCD245T 4500
how to get pivot tabe so i get PAN no. against Name.
I found an easy way to get text values in pivot table.
I create an other worksheet in wich each cell has a formula that copy the pivot table. The trick is that the formula does a lookup for the numbers in the pivot table.
The formula looks like that:
=IF(ISNUMBER(table!A1);VLOOKUP(table!A1;Code!$A$1:$B$65;2);IF(ISBLANK(table!A1);" ";table!A1))
Code is a worksheet where there is a liste of text /numbers correspondance.
As a bonus The new sheet is easier to format
Additional trick:
In my case, i encoded differents codeid with a power(2, codeId-1) so that summing then is equivalent to concatenate them.
1-A
2-B
4-C
8-D
yields :
5 - AC
14 - BCD
Hi
I want to ask if pivot can display dates in pivot field. As in a column i have customers and in row different items i want to know there last purchase date. anyone help in this??
Hello Guys, Need your help
I am doing some analysis of the cycle time of the product i.e how much time a product takes from manufacturing to the central warehouse.
I have batch numbers for the product and against them i have to pull out the diff. dates
Like the base date is from where the manufacturing start. So i have the batch number,against it's manuf. date. Now i have to pull out the date when it was quality released.
I have the quality released data but the data have duplicates, like i will have two dates or may be three for the same batch. So my main objective is to pull out the date which is latest among them.
BATCH NO. DATE of Mfg. DATE of Quality release
A1 12/4/2014 (HERE I HAVE TO PULL value)
Next Sheet
BATCH NO. DATE of Quality Release
A1 14/5/2014
a2 23/5/2016
A1 12/5/2014
A1 13/6/2014
From this sheet i have to pull up the latest date format of date here is dd/mm/yyy
TIA
[…] needed to present text instead of counts in a pivot table value column. Here is an excellent resource for Excel manipulation, in addition to an overview of pivot […]
This is great thank you.
Wow!!! Excellent!! It helped me a lot.
I am developing training tracking sheet for 200 employees with training completed date. Each employee will be attending 25 courses. How to indicate actual dates in pivot table value field.