Sum of the elements of rows of matrix

lets say i have A=[1 2 1;3 2 1;3 5 4] and i want to sum up row elements separately and show me results as "Ri=..." here "i" is number of row. in this case R1=7, R2=9. R3=6.

[Matt J]

It sounds like you really mean "sum up column elements". The elements you are summing all belong to a common column, not a common row.

Answer 1

[Matt J]

 Asum=sum(A,1);

 for i=1:length(Asum)

    disp(['R' num2str(i) '=' num2str(Asum(i))]);

 end

[Akmyrat]

Hi Matt, thanks for answer..but it is now working.

[Jos (10584)]

This code hurts, Matt J ;-)

[Matt J]

Hurts in what way? As you recommended, I do not autogenerate separate variables R1, R2, R3,...

[Jos (10584)]

:-) Indeed, you exactly did what Akmyrat asked for ...

Answer 2

[Chandrasekhar]

sum(A')

[Matt J]

This won't work if A is a row vector. Transposing is also expensive in computation time and memory if A is large.

[Chandrasekhar]

Please let us know what is best way to do this?

Answer 3

[Jos (10584)]

You do not want to store the results in separate variables R1, R2, etc., but rather as elements of a single variable R, with R(1), R(2), etc.

A = magic(3)
RowSum = sum(R,2)
help sum

[Akmyrat]

Hi jos, thanks. but sorry your code also not working.

[Jos (10584)]

What do you mean, "not working"? Did you read the help of sum?

May be you want to sum along rows rows, i.e., sum the elements in each column?

ColumnSum = sum(R,1)

Next time, be a little bit more specific ...