This is part 5 of 6 on Profit & Loss Reporting using Excel series, written by Yogesh
Data sheet structure for Preparing P&L using Pivot Tables
Preparing Pivot Table P&L using Data sheet
Adding Calculated Fields to Pivot Table P&L
Exploring Pivot Table P&L Reports
Quarterly and Half yearly Profit Loss Reports in Excel
Budget V/s Actual Profit Loss Report using Pivot Tables
This is continuation of our earlier post Exploring Profit Loss Pivot Reports.
We have learned how to change our P&L report on various data elements. We have seen how the P&L report can be changed with just few clicks.
In this post we will be learning some grouping tricks in PivotTables. We will cover grouping of dates, text fields and numeric fields. You will need to start with Monthly P&L report prepared in previous post.
Grouping Profit Loss Report based on Dates
- Right click on date field > Choose Group > Choose Quarters from dates grouping dialog box > click OK.
- Tutorial: Grouping Dates in Pivot Tables.
Once done your quarterly P&L is ready, you can still filter it on any other filed. Checkout screen cast for quarterly P&L prepared and filtered on City filed to make Quarterly P&L for Amritsar City.
Not only this, you can also drag grouped data to page area and Geography field to column area of PivotTable. Now you can filter it on Qtr1 to make Geography wise P&L for Qtr1.
[Click here to see how to do this]
This one is simple as it groups January to March period as Qtr1, April to June as Qtr2 and so on.
Grouping Dates based on Apr-Mar Financial Year
Most of the Indian companies follow April to March as Financial Year. They start with April to June as Qtr1 and finish with January to March as Qtr4. You will need different steps if you want make April to June as Qtr1 and January -March as Qtr4.
In our Data we have January 2009 to March 2009 period as Qtr 4 of 08-09 Financial Year. Grouping steps are as under
- Select January to March month columns > right click on selected columns > Choose Group.
- Rename Group1 as Q4.08-09
- Follow similar steps to Group April 2009 to June 2009 as Q1.09-10 and so on.
- [Click here to see how to do this]
- Drag the grouped field out of PivotTable in case you want to remove grouping.
The final report looks like this:
Many companies follow different Financial Year. In case your company follows May to April as Financial Year, you can select May June and July months and group them as Qtr1. You have the flexibility to select particular periods and group them. You can input name of the group as you want.
In similar way you can group 6 months to make half yearly Profit Loss Report in Excel.
Grouping Profit Loss Report Based on Text Fields
You can group data on text fields. In Geography wise P&L you can group South and East column to make P&L for South East.
You can select non consecutive columns :- Click on East column > Press Ctrl > Click on South column while you keep Ctrl key pressed. You will see that you have both the columns selected.
Select East and South Column > Right Click > Choose Group > Rename Group1 as South East.
Drag the grouped field out of PivotTable in case you want to remove grouping.
[Click here to see how this is done]
Grouping Profit Loss Report based on Numbers
You can also group data on numeric fields. We will make a PivotTable P&L grouping stores based on their size. Prepare P&L on store sizes by dropping store area field into column area of PivotTable.
Right Click on Store Area filed > Choose Group > Enter grouping parameters in Group dialog box > Click OK
You have the P&L for stores grouped based on their size.
Putting it all together – Creating a Custom Profit Loss Report Layout in Excel:
You can explore your PivotTable P&L in any combinations discussed in this post and our previous post.
So how about making South East Geography P&L for Q1 only of stores sized 4000 – 4999, like this?
It is just few clicks and your P&L will be ready , watch out screencast.
[this is a heavy screencast, so click thru if you want to watch it].
Dealing with “Cannot group that selection” error:
While grouping fields in PivotTable you may get a message saying “Cannot group that selection”. This happens due to blank date / number field or text in date / number field. You may have some blank rows in the data causing this problem. Some time you may have second copy of date field shown as Month2 or date2. This is duplicate field created in PivotTable which is already grouped. You will need to un-group this before grouping date filed again differently if required.
Download Excel file with all these example Pivot Reports:
Download Profit Loss Report Excel file and practice all these tricks on your own. [mirror download location]
What Next?
In the next part of this series, learn how to prepare budget vs. actual profit-loss reports.
Meanwhile, make sure you have read the first 4 parts of this series – Data sheet structure, Preparing P&L Pivot Table, Adding Calculated Fields and Exploring Profit Loss Report Pivot
Also check out the Excel Pivot Tables – Tutorial, Pivot Table Tricks, Grouping Dates in Pivot Reports articles to get more ideas.
Added by PHD:
- Say thanks if you like the idea and want to learn more.
- Please share your feedback and ideas for this series using comments. Yogesh and I will reply to your questions.
- Sign-up for PHD E-mail newsletter because you will get updates as new posts go online.
Yogesh is an accountant with 13 years of experience in India and abroad. His specialties are budgeting and costing, supplier accounting, negotiation of contracts, cost benefit analysis, MIS reporting, employees accounting. He writes about excel at http://www.yogeshguptaonline.com/
20 Responses to “Simulating Dice throws – the correct way to do it in excel”
You have an interesting point, but the bell curve theory is nonsense. Certainly it is not what you would want, even if it were true.
Alpha Bravo - Although not a distribution curve in the strict sense, is does reflect the actual results of throwing two physical dice.
And reflects the following . .
There is 1 way of throwing a total of 2
There are 2 ways of throwing a total of 3
There are 3 ways of throwing a total of 4
There are 4 ways of throwing a total of 5
There are 5 ways of throwing a total of 6
There are 6 ways of throwing a total of 7
There are 5 ways of throwing a total of 8
There are 4 ways of throwing a total of 9
There are 3 ways of throwing a total of 10
There are 2 ways of throwing a total of 11
There is 1 way of throwing a total of 12
@alpha bravo ... welcome... 🙂
either your comment or your dice is loaded 😉
I am afraid the distribution shown in the right graph is what you get when you throw a pair of dice in real world. As Karl already explained, it is not random behavior you see when you try to combine 2 random events (individual dice throws), but more of order due to how things work.
@Karl, thanks 🙂
When simulating a coin toss, the ROUND function you used is appropriate. However, your die simulation formula should use INT instead of ROUND:
=INT(RAND()*6)+1
Otherwise, the rounding causes half of each number's predictions to be applied to the next higher number. Also, you'd get a count for 7, which isn't possible in a die.
To illustrate, I set up 1200 trials of each formula in a worksheet and counted the results. The image here shows the table and a histogram of results:
http://peltiertech.com/WordPress/wp-content/img200808/RandonDieTrials.png
@Jon: thanks for pointing this out. You are absolutely right. INT() is what I should I have used instead of ROUND() as it reduces the possibility of having either 1 or 6 by almost half that of having other numbers.
this is such a good thing to learn, helps me a lot in my future simulations.
Btw, the actual graphs I have shown were plotted based on randbetween() and not from rand()*6, so they still hold good.
Updating the post to include your comments as it helps everyone to know this.
By the way, the distribution is not a Gaussian distribution, as Karl points out. However, when you add the simulations of many dice together (i.e., ten throws), the overall results will approximate a Gaussian distribution. If my feeble memory serves me, this is the Central Limit Theorem.
@Jon, that is right, you have to nearly throw infinite number of dice and add their face counts to get a perfect bell curve or Gaussian distribution, but as the central limit theorem suggests, our curve should roughly look like a bell curve... 🙂
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I'm afraid to say that this is a badly stated and ambiguous post, which is likely to cause errors and misunderstanding.
Aside from the initial use of round() instead of int(),.. (you've since corrected), you made several crucial mistakes by not accurately and unambiguously stating the details.
Firstly, you said:
"this little function generates a random fraction between 0 and 1"
Correctly stated this should be:
"this little function generates a random fraction F where 0 <= F < 1".
Secondly, I guess because you were a little fuzzy about the exact range of values returned by rand(), you have then been just as ambiguous in stating:
"I usually write int(rand()*12)+1 if I need a random number between 0 to 12".
(that implies 13 integers, not 12)
Your formula, does not return 13 integers between 0 to 12.
It returns 12 integers between 1 and 12 (inclusive).
-- As rand() returns a random fraction F where 0 <= F < 1, you can obviously can only get integers between 1 and 12 (inclusive) from your formula as stated above, but clearly not zero.
If you had said either:
"I usually write int(rand()*12) if I need a random number between 0 to 11 (inclusive)",
or:
"I usually write int(rand()*12)+1 if I need a random number between 1 to 12 (inclusive)"
then you would have been correct.
Unfortunately, you FAIL! -- repeat 5th grade please!
Your Fifth Grade Maths Teacher
Idk if I'm on the right forum for this or how soon one can reply, but I'm working on a test using Excel and I have a table set up to get all my answers from BUT I need to generate 10,000 answers from this one table. Every time, I try to do this I get 10,000 duplicate answers. I know there has to be some simple command I have left out or not used at all, any help would be extremely helpful! (And I already have the dice figured out lol)
Roll 4Dice with 20Sides (4D20) if the total < 20 add the sum of a rerolled 2D20. What is the average total over 10,000 turns? (Short and sweet)
Like I said when I try to simulate 10,000turns I just get "67" 10,000times -_- help please! 😀
@Justin
This is a good example to use for basic simulation
have a look at the file I have posted at:
https://rapidshare.com/files/1257689536/4_Dice.xlsx
It uses a variable size dice which you set
Has 4 Dice
Throws them 10,000 times
If Total per roll < 20 uses the sum of 2 extra dice Adds up the scores Averages the results You can read more about how it was constructed by reading this post: http://chandoo.org/wp/2010/05/06/data-tables-monte-carlo-simulations-in-excel-a-comprehensive-guide/
Oh derp, i fell for this trap too, thinking i was makeing a good dice roll simulation.. instead of just got an average of everything 😛
Noteably This dice trow simulate page is kinda important, as most roleplay dice games were hard.. i mean, a crit failure or crit hit (rolling double 1's or double 6's) in a a game for example dungeons and dragons, if you dont do the roll each induvidual dice, then theres a higher chance of scoreing a crit hit or a crit failure on attacking..
I've been working on this for awhile. So here's a few issues I've come across and solved.
#1. round() does work, but you add 0.5 as the constant, not 1.
trunc() and int() give you the same distributions as round() when you use the constant 1, so among the three functions they are all equally fair as long as you remember what you're doing when you use one rather than the other. I've proven it with a rough mathematical proof -- I say rough only because I'm not a proper mathematician.
In short, depending on the function (s is the number of sides, and R stands in for RAND() ):
round(f), where f = sR + 0.5
trunc(f), where f = sR + 1
int(f), where f = sR + 1
will all give you the same distribution, meaning that between the three functions they are fair and none favors something more than the others. However...
#2. None of the above gets you around the uneven distribution of possible outcomes of primes not found in the factorization of the base being used (base-10, since we're using decimal; and the prime factorization of 10 is 2 and 5).
With a 10-sided die, where your equation would be
=ROUND(6*RAND()+0.5)
Your distribution of possible values is even across all ten possibilities.
However, if you use the most basic die, a 6-sided die, the distributions favor some rolls over others. Let's assume your random number can only generate down to the thousandths (0.000 ? R ? 0.999). The distribution of possible outcomes of your function are:
1: 167
2: 167
3: 166
4: 167
5: 167
6: 166
So 4 and 6 are always under-represented in the distribution by 1 less than their compatriots. This is true no matter how many decimals you allow, though the distribution gets closer and closer to equal the further towards infinite decimal places you go.
This carries over to all die whose numbers of sides do not factor down to a prime factorization of some exponential values of 2 and 5.
So, then, how can we fix this one, tiny issue in a practical manner that doesn't make our heads hurt or put unnecessary strain on the computer?
Real quick addendum to the above:
Obviously when I put the equation after the example of the 10-sided die, I meant to put a 10*RAND() instead of a 6*RAND(). Oops!
Also, where I have 0.000 ? R ? 0.999, the ?'s are supposed to be less-than-or-equal-to signs but the comments didn't like that. Oh well.
How do you keep adding up the total? I would like to have a cell which keeps adding up the total sum of the two dices, even after a new number is generated in the cells when you refresh or generate new numbers.
So, how do you simulate rolling 12 dice? Do you write int(rand()*6) 12 times?
Is there a simpler way of simulating n dice in Excel?
I've run this code in VBA
Sub generate()
Application.ScreenUpdating = False
Application.Calculation = False
Dim app, i As Long
Set app = Application.WorksheetFunction
For i = 3 To 10002
Cells(i, 3).Value = i - 2
Cells(i, 4).Value = app.RandBetween(2, 12)
Cells(i, 5).Value = app.RandBetween(1, 6) + app.RandBetween(1, 6)
Next
Application.ScreenUpdating = True
Application.Calculation = True
End Sub
But I get the same distribution for both columns 4 and 5
Why ?
@Mohammed
I would expect to get the same distribution as you have effectively used the same function