Using two minus signs next to each other causes the formula to convert a return value of “TRUE” into 1 and a return value of “FALSE” into 0.
Let’s start with a simple logical condition :3 > 2 .
Apply this in excel = 3>2 returns “TRUE” . Using “—“ two minus signs together with this condition returns 1 = (3>2)
This method is mostly used in SUMPRODUCT formulas to convert the conditional arrays that evaluates to TRUE/FALSE into 1/0.
Note : SUMPRODUCT formula ignores non numeric cells. Using double minus signs technique we can command excel to convert TRUE/FALSE to 1/0.
A  B  
1 
X

Y 
2 
20

2 
3 
10

5 
4 
5

8 
5 
15

11 
6 
7

14 
7 
8

17 
8 
13

20 
Use this formula =SUMPRODUCT((A2:A8<12),B2:B8)
The first minus sign coerces the array to (0,1,1,0,1,1,0) and the second minus sign multiplies each values with negative sign [ Basic Maths : () * () = + ] (0,1,1,0,1,1,0)
So the sumproduct evaluates =SUMPRODUCT((0,1,1,0,1,1,0),(2,5,8,11,14,17,20)) returns a value 44.
You can figure out the same thing using the below formula :
=SUMPRODUCT((A2:A8>10)*B2:B8)
Superb. Thanks for sharing your knowledge.
ReplyDeleteCan you please also add one of the most power full excel tool "Turning Data into Decisions" i.e. PivotTable, PowerPivot and PivotCharts?
Really good
ReplyDeleteSo in the first example we are wanting to add the values in column B where the value in column A is less than 12.
ReplyDelete