Using Arrays To Update Table Columns
We are creating a lot of reports everyday and these reports contain a lot of data which is presented in various styles as per the requirements. The data that allows us to create the reports is usually referred as raw data and in most of the cases is stored in hidden sheets.
I am sure you all are aware of a feature called as Excel Tables OR Structured References in Excel. Excel Tables is (in my opinion) the best way to store your raw data and put Formulas in the columns where necessary, this way you eliminate the need of a Cell Based Reference formula (example =SUM(B4:B50) and replace them with =sum(YourTable[YourTableColumnName]).
Another good feature of the Excel Tables is you just need to put the formula in 1 cell and it is replicated for that column by Excel.
Sometimes these formulas take a lot of time to calculate when we have really huge data points. In this scenarios it is better to have hard-coded values instead of the formulas to gain on speed.
In this post we will learn about how we can make use of Array’s to quickly populate the excel columns with the desired results before publishing our reports and other documents.
Here is a demo of what I mean:
Below is the code that allows us to add a new column to our data table and then taking input from the Date Time column provides us with the Week Of column.
Sub UpdateWeek()
Dim myarray As Variant
Dim theRange As Range, startCellRow As Long
Dim tempStr As String
Dim myNewCol As ListColumn
‘If our column already exists then delete it
On Error Resume Next
Worksheets(“Data”).ListObjects(“cs”).ListColumns(“WeekOf”).Delete
‘adding our new column
Set myNewCol = Worksheets(“Data”).ListObjects(“cs”).ListColumns.Add
myNewCol.Name = “WeekOf”
‘Selecting the first cell of the column that contains our dates
Worksheets(“Data”).ListObjects(“cs”).ListColumns(“Date Time”).Range.Cells(2).Select
‘building a temporary Range address, this will be used to upload the entire range into the array
tempStr = ActiveCell.Address
startCellRow = ActiveCell.Row
tempStr = tempStr & “:$” & Mid(Sheets(“Data”).ListObjects(“cs”).ListColumns(“Date Time”).Range.Cells(2).Address, 2, 1) & “$”
tempStr = tempStr & LastRowInOneColumn(Mid(Sheets(“Data”).ListObjects(“cs”).ListColumns(“Date Time”).Range.Cells(2).Address, 2, 1))
‘loading the range into the array
myarray = Range(tempStr).Value
‘Looping through the array and converting each element to the relevant Week format
For i = LBound(myarray) To UBound(myarray)
myarray(i, 1) = Format(myarray(i, 1) – Weekday(myarray(i, 1), vbMonday) + 1, “ddd dd-mmm”)
Next
‘Setting the range address for our output column
Set theRange = Range(Cells(startCellRow, Worksheets(“Data”).ListObjects(“cs”).ListColumns(“WeekOf”).Range.Column), Cells(UBound(myarray) + (startCellRow – 1), Worksheets(“Data”).ListObjects(“cs”).ListColumns(“WeekOf”).Range.Column))
‘storing the values from our array to the WeekOf Column
theRange.Value = myarray
End Sub
Let’s Understand the code
We first delete the column if it is already existing to make sure we always get the new values as output. This is done by the below line of code.
Worksheets("Data").ListObjects("cs").ListColumns("WeekOf").Delete
Once we have deleted the column, we add it again as a blank column and change the name to “Week Of”.
Set myNewCol = Worksheets("Data").ListObjects("cs").ListColumns.Add
myNewCol.Name = "WeekOf"
After this we need to select the first cell of the column that contains the Date Time.
Worksheets("Data").ListObjects("cs").ListColumns("Date Time").Range.Cells(2).Select
Once we have selected the first cell of you Date Time column we then make use of the LastRowInOneColumn function to get the last row and create a range address. We use this range address to assign all the values contained in the Date Time column to an array.
tempStr = ActiveCell.Address
startCellRow = ActiveCell.Row
tempStr = tempStr & ":$" & Mid(Sheets("Data").ListObjects("cs").ListColumns("Date Time").Range.Cells(2).Address, 2, 1) & "$"
tempStr = tempStr & LastRowInOneColumn(Mid(Sheets(“Data”).ListObjects(“cs”).ListColumns(“Date Time”).Range.Cells(2).Address, 2, 1))
‘loading the range into the array
myarray = Range(tempStr).Value
Once we have loaded all the Date Time values into an array, we do a simple For loop to change the value in the array to the relevant Week Of
For i = LBound(myarray) To UBound(myarray)
myarray(i, 1) = Format(myarray(i, 1) - Weekday(myarray(i, 1), vbMonday) + 1, "ddd dd-mmm")
Next
We perform this operation on the same element and store the modified value in itself.
Once we have all these done, we need to define the Output range, that is where we need to the Week Of values to be stored. This is done by using the Range and Cell functions.
Set theRange = Range(Cells(startCellRow, Worksheets("Data").ListObjects("cs").ListColumns("WeekOf").Range.Column), Cells(UBound(myarray) + (startCellRow - 1), Worksheets("Data").ListObjects("cs").ListColumns("WeekOf").Range.Column))
'storing the values from our array to the WeekOf Column
theRange.Value = myarray
And lastly we assign all the values stored in the array to the new range address we have create above.
Download Demo File
Click here to download the demo file & use it to understand this technique.
What about you? Do you use them often? Please share your experiences, techniques & ideas using comments.
If you are new to VBA, Excel macros, go thru these links to learn more.
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About Vijay
Vijay (many of you know him from VBA Classes), joined chandoo.org full-time this February. He will be writing more often on using VBA, data analysis on our blog. Also, Vijay will be helping us with consulting & training programs. You can email Vijay at sharma.vijay1 @ gmail.com. If you like this post, say thanks to Vijay.
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