# How can I sum the elements in a vector row without using the sum function or any form of loops?

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Keaton Winder on 26 Mar 2020
Commented: Stephen Cobeldick on 26 Mar 2020
How can I sum the elements in a vector row without using the sum function or any form of loops?

per isakson on 26 Mar 2020
Edited: per isakson on 26 Mar 2020
This is one way
>> vec = (1:12);
>> vec*ones(12,1) % replace '12' by length(vec)
ans =
78
and check if that's the correct result
>> sum(vec)
ans =
78

#### 1 Comment

Stephen Cobeldick on 26 Mar 2020
+1 simple and precise

Peng Li on 26 Mar 2020
I don't quite understand your point about not using the function sum. But it is definitely possible to not use any form of loop.
suppose A is a matrix. sum(A) or sum(A, 1) calculates the sum along the first dimension (row). It gives the sum of each column, thus resulting you a row vector.
sum(A, 2) calculates the sum along the second dimension (column), thus throwing you a column vector with each element the sum of each row.