managing two variables in sum function

Hi, I want to manage two variables in a sum function in a way that sum(i*cos(ik)); which i=1:N , k=1:M but I want only want the SUM with respect to i and create a vector which has M values in other way i should be sumed but k only takes a value each time. what can I do? If I should use loops how can I do that? Thanks in advance

Answer 1

[Azzi Abdelmalek]

N=10;
M=20;
ii=1:N
for k=1:M
 som(k)=sum(ii.*cos(ii*k));
end

[Raj Patel]

No

Answer 2

[Steven Lord]

Use element-wise operations to create a matrix of data to sum then call sum with a dimension input.

[c, r] = meshgrid(1:5, 1:6);
M = c.^r
sum(M, 1) % Sum down columns
sum(M, 2) % Sum along rows