I got a arrayfunction that is returning a matrix. I want to edit this to only return a vector, where this vector contains the sum of each row. I tried applying sum(), but that summed every element of the matrix. It is important to keep it just to one formula, not one array-formula for each row.
I am working in Google Spreadsheet, but If you only know a solution for Excel, please post it, and I might be able to convert it.
In Excel You can also use this version
=SUMIF(OFFSET(A1:C15,ROW(A1:C15)-ROW(A1),0,1),"<9.99E+307")
confirmed with CTRL+SHIFT+ENTER
assuming your matrix is in A1:C15
That has a small advantage over MMULT - it still works if some of the cells in A1:C15 are blank or don't contain numbers
However you can amend the MMULT version to work with a partially populated range too, i.e. with this version
=MMULT(IFERROR(A1:C15+0,0),TRANSPOSE(COLUMN(A1:C15)^0))
again confirmed with CTRL+SHIFT+ENTER
In Google sheets I couldn't make the SUMIF version work - but the MMULT option works with the addition of "arrayformula" function, i.e. this version:
=arrayformula(mmult(iferror(A1:C15+0,0),transpose(column(A1:C15)^0)))
It sounds like you want the OFFSET function. I'm going to use MATRIX() as a stand-in for whatever function you have that is returning a matrix. If you want to show sums for the first 3 rows of that matrix, the formulas would be as follow:
=SUM(OFFSET(MATRIX(),0,0,1)
=SUM(OFFSET(MATRIX(),1,0,1)
=SUM(OFFSET(MATRIX(),2,0,1)
The format is OFFSET(Reference,Rows,Columns,[Height],[Width]). There's a more detailed explanation of the arguments on the MS Support page but the key points is that Rows,Columns describes how far to offset from the top-left cell in the Reference range and Height,Width describes how large to make the array from that offset cell. You want it to be 1 row high and the same width as the original so use 1 for Height and just leave Width blank as it will default to be the same width as Reference.
This question is a duplicate of one over at Stack Overflow. If you want to return the array, the formula is:
MMULT(MATRIX(),TRANSPOSE(COLUMN(MATRIX())^0))
Note the lack of an equal sign because this formula by itself in a cell will return the #VALUE! error. Hopefully, this is something you can work with in your application. I tested it to make sure it worked by summing those values with the array formula:
{=SUM(MMULT(MATRIX,TRANSPOSE(COLUMN(MATRIX)^0)))}
Of course, this is just a needlessly complicated version of =SUM(MATRIX()) but it worked as a test. In Excel, it also allows you to step through the calculation with the Evaluate Formula function on the Formulas ribbon and it'll show the array result given by MMULT.
