Welcome to Power Mondays. Every Monday, learn all about Power BI, Power Query & Power Pivot in full length examples, videos or tips. In the first installment, let’s take a look at something we all can related to – Money.
We all know that Power BI is good for creating awesome visual experiences. Today let me share another fun way to use Power BI – to build a calculator. Learn how to create nest egg calculator in this Power BI parameter example tutorial.
This is what our output looks like:
Ready to learn how to do this in Power BI? Read on then…
Creating a nest egg calculator with Power BI Parameters – Step by step tutorial
We will use a very interesting and little known feature of Power BI – what-if parameters to build our nest egg calculator.
Step 1: Defining goals for the nest egg calculator
Just as building a large nest egg requires patience and planning, our nest egg calculator too needs some planning. But what planning you say? Just thinking out loud what our calculator should look like and what it should do is enough. So on that note, let’s define some goals:
- We have two kinds of savings – regular (monthly) and one time (already invested)
- The expected rate of return is different for each type of saving
- We want to see how the nest egg will grow over time, for example, next 30 years
Let’s say we want to figure out future value of 3 monthly investments and an existing investment. Each has their own expected rate of return.
We need to calculate value of investment at the end of year for next 30 years. ie Future value of our investment.
Step 2: Set up Power BI parameters to capture inputs
As each of our inputs can change, we need something that let’s us toy with the inputs. Guess what? We will use Parameters. This feature of Power BI let’s you add a what-if parameter to your workbook.
When you add a what-if parameter, Power BI does two things:
- Creates a table with all possible parameter values
- Creates a harvester measure that tells you which value is selected by user
To insert a parameter:
Open blank Power BI workbook and using what-if parameter button in the modeling tab, insert a parameter, as below.
Power BI Parameter Example – Demo
Now, repeat this step for 7 more times, so that we end up with 8 parameter tables, as described below.
At the end of this step, we will have 8 tables and 8 measures.
Lay out the parameter slicers like this on the canvas:
Note: You need to enable slider for the slicers.
Step 3: Create a table for forecast
We want to forecast the future value of investments for next 30 years. That means, we need to know the future value for each of those 30 years. If only, we had a table with numbers 0 to 30, then we can write some sort of DAX formula to calculate the FV.
To start off, let’s generate a table with numbers 0 to 30 (31 rows). You can do this in either Power Pivot (using GENERATESERIES() DAX formula) or in Power Query using the query ={0..30}
Let’s do this in Power Query. To create the forecast table in PQ:
- Go to home > get data > blank query
- When a blank query is created in PQ, in the formula bar type ={0..30} and press enter
- PQ will create a series of 31 numbers (starting from 0 and ending at 30) as a list
- Convert this list to a table using List tools > Transform ribbon.
- Add any other columns (derived) if you want.
- Name this query as Projection and load it to Power BI.
Step 4: Calculate forecast values
Now that our parameters and forecast table are ready, we can calculate future values of each investment. If you have this data in Excel, you can use FV() function to calculate the value. Unfortunately, Power Pivot doesn’t have FV() DAX formula. So how?
Simple, we can write the actual algebra.
The equation for future value of P payment for n periods at r interest rate is:
FV = P*(((1+r)^n – 1) / r)
For example, for [Amount 1 Value] of $100 invested at [Growth 1 Value] for 5 years would be:
=[Amount 1 Value] * (((1+[Growth 1 Value])^5 – 1)/[Growth 1 Value])
But wait, we are investing monthly…
As we are investing monthly instead of yearly, we need to to change r & n to r/12 and n*12.
So the final formula for future value after 5 years will be:
=[Amount 1 Value] * (((1+[Growth 1 Value]/12)^(5*12) – 1)/([Growth 1 Value]/12))
Replacing the division with DIVIDE() DAX formula, we get:
= [Amount 1 Value] * DIVIDE(((1+[Growth 1 Value]/12)^(5*12)-1),([Growth 1 Value]/12),1)
Calculating for all years
The above DAX formula works only for 5th year. How to calculate for any year?
Simple, we create a measure called as [selected year] which when used in a visual (like chart or table) will return different years. Something like =MAX(Projection[year]) should do.
Replacing 5 with [selected year], we get:
Amount 1 FV := [Amount 1 Value] * DIVIDE(((1+[Growth Pct 1 Value]/12)^([selected year]*12)-1),([Growth Pct 1 Value]/12),1)
Create 2 more such measures for Amount 2 FV and Amount 3 FV.
Calculating Future Value of [Amount have]:
In case of starting amount (existing investments), we can use compound interest logic to calculate future value.
The future value of amount P invested at r interest over n periods is given by this formula:
=P*(1+r)^n
Here is the measure for same:
Already have FV := [Already have Value]*(1+’Growth Pct (have)'[Growth Pct (have) Value])^[selected year]*1000
Remember, already have value is entered in $000s, so we must multiply the result with 1000.
Step 5: Visualize the result
And now comes the best part. We visualize all the yummy results calculated by our measures.
Start by inserting a stacked area chart. This is perfect for our calculator.
Add years as axis. Add [Amount 1 FV], [Amount 2 FV], [Amount 3 FV] and [Already have FV] as values. Your chart is ready.
When you put years on X axis of this visual, Power BI (thru Power Pivot) calculates the future value of all 4 investments for each year and shows the output as a stacked area chart. Cool no?
Now as you play with the sliders, the future amounts change. Go ahead and find out how much your nest egg will be worth. And then start working towards it.
See all of it in action – Live retirement savings calculator
Want to play with this but not near Power BI? Just use the embedded Power BI visual below to play and find out how much your nest egg will be worth.
Download Nest Egg calculator Power BI workbook
Click here to download the PBIX file for this. Play with it to learn more.
Note: This is made with July 2018 release of PBI, but should work in any recent version. If you notice anything funny, drop a comment so I can help.
Want more Power? Check out these amazing examples
If you like Power BI, please check out these examples to see other creative ways to use it.
- Which countries did better – Commonwealth Games 2018 dashboard in Power BI
- Homer Simpson in Power BI – D’oh counter
- Bitcoin what-if calculator in Power BI [Data Chant]
- Visual flair with custom backgrounds [Power Pivot Pro]
- Collapsible slicer pane for your Power BI Reports [Data Veld]
Excited about Power Mondays? Tell me what you want to see more?
I am super excited about Power Mondays. Every Monday, you will see the mighty magic of various Power tools. If you think I should talk about a certain business problem or concept, please post your suggestion in the comments. I will research and write about it on the blog in a subsequent Power Monday episode.
19 Responses to “How to Distribute Players Between Teams – Evenly”
An excellent solution, especially for large data sets.
Another solution without using solver would be to assign the player with the highest score to Team 1, the 2nd to team 2, 3rd to team 3, 4th to team 3, 5th to team 2, 6th to team 1, 7th to team 1 and it continues. This method would end up with a Std Dev of 0.001247219. This works best with a distribution with lower Std Dev for the dataset.
Full Disclosure: this is not my idea, remember reading something a few years ago. Think it may have been Ozgrid
thinking back I now remember why I read about it. About 10 years back I had to distribute around 300 team members into 25-30 odd teams. Used this method based on their performance scores. I used the method I described to do this and the distribution was pretty fair.
Solver would have saved me a ton of time though 🙂
I think the issue with you first Solver approach was that you took the absolute value of the sum of team deviations (which should always be zero except for rounding) instead of the sum of the absolute values (which is a reasonable measure of how unbalanced the teams are).
Here's another simple algorithm you could use: you start from the top (with players sorted from high to low), and at each step allocate the next player to whichever team has the smallest total so far. You can implement it dynamically with some formulas so it will update automatically when the data changes.
If the scores were more widely distributed (so that this might end up with not all teams the same size), you could add a constraint to only pick among the teams which currently have fewest players at each step, or just stop adding to any team when it hits its quota.
When I tried it on the sample, I got the three teams below, with a STDEV of 0.000942809 (i.e. about half of what Solver got to).
Team 1: John, Hugo, Tom, Josh, Eric, Zane, Charles, Andrew
Team 2: Barry, Michael, Kenny, Joe, Xavier, Patrick, Oliver, William
Team 3: Henry, Steven, Ben, Frank, Kyle, Edward, Cameron, Lachlan
Thanks for sharing!
Hi,
I was looking at all the solutions and this is closest to what I intended to do. I am dividing a bunch of players into 3 soccer teams. Players availability is also a factor while deciding the teams.
So the steps the excel needs to do is as follows:
1) In availability column if "yes" go to next
2) Equally divide 'Goalkeepers', 'Strikers', 'Defenders' basis their quality
So the end result gives each 3 teams a balance of players playing at different positions.
Can this be done on Google spreadsheet with only availability as an input from the user and rest calculates by itself.
Sorry for asking such a pointed question, but I have been struggling to find a solution for it for sometime now!
Hi Ishaan,
I am working on a similar problem at the moment, so I am wondering if you ever found a solution and if you are willing to share what you did.
Hi everyone, this is a variation of the famous Knapsack Problem https://en.wikipedia.org/wiki/Knapsack_problem.
I had to use a VBA implementation recently as part of a problem, where we ar trying to allocate teams of an organization into different locations (we are a large company with many different team). The goal was to optimally allocate teams to individual buildings without putting too many teams into one building and not splitting teams apart.
As we had around 400 teams of different sizes, solver couldn't handle it anymore. Luckily there is a Knapsack algorithm implementation in VBA readily available on the internet :).
I also went with a heuristic approach first!
An interesting mathematical solution but what if Eric and Xavier can't stand each other or Patrick is best friends with Steven - the real life problems that effect "even" teams.
@Joe
You can add more criteria like
If Eric and Xavier can't stand each other
=OR(AND(E15=1,E16=1),AND(F15=1,F16=1),AND(G15=1,G16=1))
It must be False
If Patrick is best friends with Steven
=OR(AND(E5=1,E17=1),AND(F5=1,F17=1),AND(G5=1,G17=1))
It must be True
Note that the 2 formulas above are exactly the same
except for the ranges
One must be True = Friends
One must be False = Not Friends
Nice Post!
Just one question What if number of players are not even or equally divisible.
Nice post Hui!
I download your workbook and just try to change in options the Precision Restriction from 10E-6 to 10-8 and the Convergence from 10E-4 to 10E-10. The process take almost the same time, but the results was great.
The standard deviation I got was 0,000471.
Team 1: John, Tom, Kenny, Frank, Eric, Xavier, Edward, Zane
Team 2: Steven, Hugo, Ben, Joe, Josh, Oliver, Cameron, William
Team 3: Barry, Henry, Michael, Kyle, Patrick, Charles, Andrew, Lachlan
Great application of Solver! Thanks for the link!
Great explanation. Well done... However, I tried with 6 teams of 4 players and solver never did finish.
How about vba code for the same data set.
I have 3 column A B C wherein A has text and B has number Wherein C is blank. And in C1 been the header C2 where I want the name to come evenly distributed the number which is in Column B.
My Lastcolumn is 1000.
Sorry if I'm being slow here, but how is 'Team Score' calculated? I've gone through the explanation several times but it seems to just appear.
@Hrmft
This process uses the Solver Excel addin
Solver is effectively taking the model and trying different solutions until it gets a solution that meets all the criteria
Then solver puts the solution into the cell and moves to the next cell
So yes it appears to "just appear"
Hi ! Thank you so much ! Works great 🙂
I cannot get the fourth Equation to work in my excel spreadsheet
You have =($E$2:$G$25=0)+($E$2:$G$25=1)=1 as a SUMIF solution, I have, =($F$2:$H$13=0)+($F$2:$H$13=1)=1 as my solution but it does not work. The only thing I changed is the ranges. Any suggestions?
Thank you.
Jim
I cannot get the fourth Equation of TURE or FALSE statements to work in my excel spreadsheet You have =($E$2:$G$25=0)+($E$2:$G$25=1)=1 as a SUMIF solution, I have, =($F$2:$H$13=0)+($F$2:$H$13=1)=1 as my solution but it does not work. The only thing I changed is the ranges. Any suggestions?
Sorry I left some of it out in the previous question,
Thank you. Jim