One of the most asked questions within the posts and Forums at Chandoo.org is “How Does Sumproduct work ?”.
Rahul recently asked for an example in Excels Sumproduct Formula post; Comment No. 55.
So today in Formula Forensics we will take a look at just that with a few worked examples.
Sumproduct
Excels help defines Sumproduct as:
So what are these arrays referring to:
An array in Excel can be :
A manual Array: {10;20;30}
A Range: A1:A3
A Named Range: MyRange1
Where MyRange1 is defined as a defined range in the Name Manager.
A Named Formula: MyRange2
Where MyRange2 is defined as a Formula returning a range in the Name Manager.
Lets look at each
You can follow along in the Example file on Sheet1
An Array
In C2 type: =SUMPRODUCT({10;20;30})
Excel will display 60, which is the Sum of the array elements =10+20+30
A Range
C7: =Sumproduct(C4:C6)
Excel displays 60, which is the Sum of the cells from the range C4:C6 =10+20+30
A Named Range
In the Name Manager or Name Box define a Named Range
MyRange1: =Sheet1!$C$4:$C$6
Then in C10 type:
C10: =Sumproduct(MyRange1)
Excel displays 60, which is the Sum of the range elements =10+20+30
A Named Formula
In the Name Manager define a Named Formula
MyRange2 =OFFSET(Sheet1!$C$3,1,0,3,1)
Then in C12 type:
C12: =Sumproduct(MyRange2)
Excel displays 60, which is the Sum of the range elements from cells C4:C6 =10+20+30
You may be asking why use Sumproduct when we can use a simple Sum to add up 3 numbers?
The answer is to show you what Sumproduct is doing, it is Adding up each Array element.
What about the “Product” part of Sumproduct ?
Remember back at the start where we saw the Definition of Sumproduct,
SUMPRODUCT(array1, [array2], [array3], …)
Only Array 1 is required, Array 2, Array 3 etc are optional, that’s what the square brackets [ ] mean.
Multiple Arrays
Goto Sheet 2 in the Example file:
We will look at a simple example using two arrays
The data consists of Sales data.
Often we want to know what the total sales are
We do this by adding a Sales column
Which multiplies the Qty and Price columns
And then Sum (Add) up this new column
Returning our Total Sales of 15,000
Now we can manually check the above as the numbers are simple eg: 100*20 = 2,000 etc
And we can sum up the Sales and see that we in fact had total sales of 15,000
Well this is exactly what Sumproduct is made to do:
In a Blank cell enter: =SUMPRODUCT(D4:D8,E4:E8)
Excel will return 15,000.
So what is Sumproduct doing?
Lets look inside and see what’s going on
In the Example File, Sheet2, H1 there is a copy of the data laid out as below
Note that our formula =SUMPRODUCT(D4:D8,E4:E8)
Has two Arrays
Array 1: D4:D8
Array 2: E4:E8
Note that each corresponding Array Element is multiplied together
100 x 20
20 x 200 etc
These are the products of the two Arrays
Finally the Products are Added together and the correct answer 15,000 is returned.
So Sumproduct is the Sum of the Products of the Arrays
Of course we can extend that to a large number of Arrays, columns in this case, if we wish.
Sumproduct with Logic
In the above two examples we saw that Sumproduct can Sum a single Array and can Sum the Product of two or more Arrays.
We can use that to our advantage and build logic into the arrays, allowing us to optionally include some array elements and leave out others.
How?
Sumproduct will always add up the product of all Arrays.
So by including an Array where the elements within the Array that we don’t want to Sum are Zero and the Elements within the array that we do want to Sum are 1 we can control what is included in the final Summation.
Goto our Example File on Sheet3
Lets say we only want to include the Sales from our Northern Region
One way to do this is to purely delete the other entries
But what if we could do that without altering our worksheet or there are thousands of rows of data?
This is where Sumproduct comes into its own.
What we need to do is add some logic to our equation, effectively doing:
Lets try it with Sumproduct
In Cell F12: type =SUMPRODUCT(D4:D8,E4:E8,{FALSE;TRUE;FALSE;FALSE;TRUE})
Excel displays a –
Excel doesn’t know what to do with the True/False and so converts them to 0
We can force excel to evaluate these as numbers by adding a simple “1*”
In F14: Type =SUMPRODUCT(D4:D8,E4:E8,1*{FALSE;TRUE;FALSE;FALSE;TRUE})
Excel now displays 5,000 the total sales from the North
To see what has happened in F16 type: 1*{FALSE;TRUE;FALSE;FALSE;TRUE}, but don’t press Enter press F9 instead.
Excel displays ={0;1;0;0;1}
The use of the 1* has converted each of the Array elements from a True/False to a 1,0 respectively.
So our 3 arrays are now:
Now adding an Array of 1*{FALSE;TRUE;FALSE;FALSE;TRUE} every time we wanted to add some numbers isn’t a practical solution.
Excel has the ability to work construct an Array on our behalf!
In E18: enter =SUMPRODUCT(D4:D8,E4:E8,1*(C4:C8=”North”))
Excel will display 5,000
So 1*(C4:C8=”North”) is exactly equal to our previous array 1*{FALSE;TRUE;FALSE;FALSE;TRUE}
1*(C4:C8=”North”) = 1*{FALSE;TRUE;FALSE;FALSE;TRUE}
At the heart of this is that Excel is evaluating each cell in the Range: C4:C8 against our required logic =”North” and setting up an Array for us internally.
Simplify
The power of Sumproduct is therefore in that we can now simplify and extend
In cell E20 type: North
In cell F20 type: =SUMPRODUCT(D4:D8,E4:E8,1*(C4:C8=E20))
Excel will display 5,000
This simple addition allows us to vary the Summation based on the value in E20
We don’t need to multiply our logic array by 1, we can actually use any number or another Array.
In cell F22 type: =SUMPRODUCT(D4:D8,(E4:E8)*(C4:C8=E20))
This works as (C4:C8=E20) is returning an Array of True/False which get converted to an array of 1/0’s when subject to any maths.
The Math in this case is the multiplication by the 2nd Array (E4:E8)*(C4:C8=E20)
In Cell F24 type: =SUMPRODUCT(Qty, Price *(Region=SalesRegion))
Excel will display 5,000
But notice that by using Named Ranges/Formula how simple the logic of the equation has now become.
Rahul’s Question (Multiple Criteria):
In Comment No. 55: Rahul asked, “Can you give an example work sheet of above example”
Sheet 4 in the Example File is the answer.
In Cell C23: type: =SUMPRODUCT(- -(A2:A21=”Luke Skywalker”),- -(B2:B21=”West”),C2:C21)
Excel will display 141, which is the sum of the Sales made by Luke Skywalker in the West Region.
However using what was learned above, this is better simplified to:
C26: =SUMPRODUCT((Name=SalesMan)*(Region=SalesRegion)*Sales)
The Double Unary
In the formula above Chandoo has used what is known as a Double Unary, which is 2 – signs next to each other (I have inserted a space above to make it more legible).
Two – signs are the same as saying
– -(A2:A21=”Luke Skywalker”) = -1 x -1 x (A2:A21=”Luke Skywalker”)
-1 x -1 is 1
Technically this is the most efficient way for Excel to perform any maths on the Array
– -(A2:A21=”Luke Skywalker”)
So that the Array of true/Falses made by (A2:A21=”Luke Skywalker”) is converted to an Array of 1/0’s for use in Sumproduct.
At the slight expense of speed but for improved readability and understandability by others I prefer the use of 1* instead of – – and you will mostly see that convention in my posts.
Chandoo: – –(A2:A21=”Luke Skywalker”)
Hui: 1*(A2:A21=”Luke Skywalker”)
In fact any maths performed on the array will convert its contents to an array of 1/0’s, so long as the maths doesn’t change the Arrays values
For a real good discussion on this topic have a look at the post The Venerable SUMPRODUCT at ExcelHero.com
Other Links to Sumproduct
http://chandoo.org/wp/2009/11/10/excel-sumproduct-formula/
http://chandoo.org/wp/2011/05/26/advanced-sumproduct-queries/
http://chandoo.org/wp/tag/sumproduct/
http://www.excelhero.com/blog/2010/01/the-venerable-sumproduct.html
DOWNLOAD
You can download a copy of the above file and follow along, Download Here.
OTHER POSTS IN THIS SERIES
You can learn more about how to pull Excel Formulas apart and what makes them tick in the following post:
FORMULA FORENSICS NEEDS YOUR HELP !
I am running out of ideas for Formula Forensics and so I need your help.
If you have a neat formula that you would like to share and explain, try putting pen to paper and draft up a Post as Luke did in Formula Forensics 003. or like above.
If you have a formula that you would like explained but don’t want to write a post also send it in to Chandoo or Hui.
XMAS BREAK
This will be the last Formula Forensics Post for 2011, but rest assured that we will be returning in early 2012.
I’d like to take the opportunity to thank Chandoo for allowing me the space and freedom to post pretty much what ever I’ve wanted at Chandoo.org. I hope you have enjoyed my contributions to the Chandoo.org community over the past year.
On behalf of Eva and myself I’d like to wish you all a very Merry Xmas and a Happy and Safe New Year ahead
Hui…
28 Responses to “2010 Calendar – Excel Template [Downloads]”
[...] Download and print the calendars today. You can add notes to individual dates or complete … [...] Uni Ego / Free 2010 Calendar – Download and Print Year 2010 Calendar today [...]
Any chance on a 2016 calendar?
Afternoon,
I have one similar calander that I added conditional formatting to so that I could highlight any planned factory holidays. I think i "borrowed" the formula from another calander so I won't post it here.
I also added week numbers to it using the formula =WEEKNUM(MAX(C6:I6)) Where C6:I6 is the range of dates in that give week. It works fine on most of the months but return strange values on other months (Week 6 in October?) I can't see any logic behind why it does this.
Any suggestions for an alternative formula to give the week numbers?
Regards,
William
Hi Chandoo,
I've added a new feature on your spreadsheet.
This control can be useful for all the sheets where you need to check dates.
Cheers
http://cid-69a78592a23a8438.skydrive.live.com/self.aspx/.Public/2010-calendar%5E_Miguel.xls
Hi Chandoo,
Nice calendar.
Till now whichever calendar I saw in Excel, it contained only the outline sheet.
Good to see monthly views and the mini view too.
Liked the mini view much. 🙂
-Nimesh
@William: This weeknum may be because the input dates to max are not properly formatting as excel dates.
Good tip on the conditional formatting and holidays btw...
@Migueal: Now that is super awesome. This is the reason why I love to blog. Readers will always one up me with such cool alternatives. Thank you for sharing this with us.
@Nimesh: You are welcome 🙂
is it possible to get the Notes section on the outline page to display the notes added to the month page for a specific date?
So if you add thing for January 2nd, and then select January 2nd those notes appear on the outline page
@Shish... You can do that using some formula magic. I would not recommend pushing excel to that as outlook / google calendar / icalc etc. do exactly that much more elegantly.
[...] Perpetual Excel Calendar – Free Downloadable Template [...]
Happy christmas to all of you!
This is really awesome. The nicest calender I've seen for Excel. I also like Miguels version of the sheet.
Just one "feature" is missing to me. As I live in Germany - where weeks start on Monday - I'd like to change this. Could someone please give me a hint how to do this?
Thanks in advance
Jörg
Hi Chandoo, I’ve added some new features on your spreadsheet with your permission.
Check it here:
http://cid-6b219f16da7128e3.skydrive.live.com/self.aspx/.Public/Calendar%5E_Pedro.xlsm
Miguel, this calendar is translated to Spanish language.
Jörg, this new approach allows us to start weeks on Monday.
Also it's possible to start weeks on Sunday if you enable Excel macros and push the arrows.
Best Regards,
Pedro.
@Pedro.. superb stuff.. thanks for sharing the file with all of us.
Hi Chandoo, for dates before March 1, 1900 our calendars are wrong.
In Microsoft Excel, DATE, EOMONTH, WEEKDAY functions return an incorrect result between Monday, January 1, 1900 and Wednesday, February 28, 1900.
See this page: http://support.microsoft.com/kb/214326/en-us/
Microsoft Excel incorrectly assumes that the year 1900 is a leap year in all Excel versions.
That's the reason why our calendar versions only work from March, 1, 1900 until December, 31, 9999.
Your comments are welcome.
Pedro.
@Pedro.. Thanks for pointing that out. wow... This reminds me of the Joel Spolsky's first BillG review - http://www.joelonsoftware.com/items/2006/06/16.html (read it, I am sure you would love it.) when Bill out of blue asks about date time implementations for VBA (which Joel is the program manager for...)
Thanks for sharing the URL too... Here is a specially made, chocolate sprinkled, extra fluffy donut for you 🙂
Hi Chandoo, thanks a lot for the donut but I prefer it without chocolate!
Always it's good to know a little history of Excel.
The Joel Spolsky’s last BillG Excel review was about the "Hall of Tortured Souls"
(See this Excel 95 Easter Egg here: http://www.eeggs.com/items/719.html)
Do not miss the humor!
@Chandoo.. I just return with a new calendar version.
http://cid-6b219f16da7128e3.skydrive.live.com/self.aspx/.Public/calendar-pedrowave.xltx
It helped me to practice conditional formatting, formulas to show check boxes, data validation drop down list, find out Thanksgiving Day's date for any year, how to find dates of public holidays using Excel, all reading your wonderful posts!
Perpetual Calendar Spanish version starting weeks on Monday:
http://cid-6b219f16da7128e3.skydrive.live.com/self.aspx/.Public/calendario-pedrowave.xltx
Main characteristics:
- Not macros.
- Select a year from 1900 to 9999 with a dropdown listbox.
- All date fields with the real date format.
- Easy language change of day of the week and month names because are also dates.
- Hide Saturdays and/or Sundays.
- Week starting on Sunday or Monday.
- Week and month numbers.
- Hyperlink between sheets.
- Consistent colors to Holidays, Diary and Events dates.
- Easy change of Holidays by country.
- Include 80 World Days and you can add more.
- A diary with my birthday and 50 more programable appointments.
- Check box to hide individual dates or all.
- Holidays, diary and events text are showed on each month's sheet.
- Ranges defined with Name Manager variables.
I'll appreciate if you make me some suggestions to improve this calendar.
Pedro.
Please, I need help!
I like all calendar from Pedro, thank you for them. Let me show my problem:
I have 2 excel cells (for example AE12 and AE13) which mean the starting and the ending date of my duty. I need a macro to insert sheets with label YEAR. MONTH (for example 2010. August or similar) with the proper datas between the two dates. Is it possible?
Thank you for reading me and sorry about my terribel english! 🙂
Hello Pedro,
Thanks so much for the modified calendar template. I love the extra functionality you added. Is there any way you could upload an unlocked version? I wanted to change some of the comments and data validation so I could use it for one of my applications.
As for feedback on potential improvements, with all the additions you made the file runs pretty slow. I'm sure this has to do with all the interconnectivity between the various tabs, but if there is a way to use less memory via more efficient formulas or something else I think this would make it easier to use. I have a brand new computer and with it running alone the response was pretty slow. One of the changes I'm making is changing the order of the months to match my company's fiscal year, so maybe something to automate a change like that could be useful.
Cheers,
Peter
Peter, my calendars are unlocked but you need Excel 2007 and 2010 versions to open them.
Now I return with a new Programmable Task Calendar:
http://cid-6b219f16da7128e3.office.live.com/view.aspx/.Public/Calendario%20de%20Tareas.xlsx
Wath an introductory video here:
http://pedrowave.blogspot.com/2010/10/programmable-task-calendar.html
This new calendar allows to select the start month to match the school and fiscal year.
This is great stuff Chandoo and company
Wanted to know if someone had built something similar
I need to store one Excel Sheet on this calendar that has all the holidays
US Holidays appear in RED
UK Holidays appear in Blue
Meetings appear in Green
Submissions appear in Orange
Is there a way I can store the list in a separate worksheet and all the calendars get updated with this?
Thanks
[...] Calendars: Year 2010 Excel Calendar | Year 2009 Excel [...]
please tell me "how to convert Rs.10000/- in to words through excel formula
[...] is all! http://chandoo.org/wp/2009/12/11/2010-calendar-excel-template-downloads/ See more Templates at http://www.vertex42.com/ Share this:Like this:LikeBe the first to like this [...]
Greetings,
Thanks for this wonderful excel vacation tracker. I notice that the tracker only has three months November, December and January 2015, however, I would like to add the other ten months for 2014. Can you please instruct me on how I can add the other months?
Thanking you in advance.
Hi Chandoo,
Calendar: can this be printed as single sheet 8.5x11 inch per month
kanu
@Kanu
Yes,
You can resize it to fit
WOW! I just searching some of like this, that help me.
Thank you for sharing.