aaSumEveryOther j3andc.xls 



 A  B  C  D  E  F  G  H  I 

1         0  Mth 

2  4  9  6  5  7  6   2  Nth 

3         17  

4  2        13  

5  1         

6  7         

7  2         

8  4         

9  4         

10          



The formula
=SUMPRODUCT((MOD(COLUMN(A2:F2)CELL("Col",$A2)+H1,H2)=0)*(A2:F2))
sums every Nth value in a horizontal range.
The formula
=SUMPRODUCT((MOD(ROW(A4:A9)CELL("Row",$A4)+H1,H2)=0)*(A4:A9))
sums every Nth value in a vertical range.
H1value is the parameter that indicates the position from which to start the summing.
H2value indicates every Nth value to sum.
When H1 = 0 and H2 = 2, the following values
{4,0,6,0,7,0} in the horizontal range, and
{2;0;7;0;4;0} in the vertical range are summed.
When H1 = 1 and H2 = 2, the following values
{0,9,0,5,0,6} in the horizontal range and
{0;1;0;2;0;4} in the vertical range are summed.
This message was edited by Aladin Akyurek on 20020912 10:00