How to plot the sums of the columns in a matrix using a for loop?

I am trying to plot the column number of matrix J versus the sum of that column using a for loop. The size of the matrix is 201 by 201. The plot should look like a sine wave, but it is not coming out correctly. This is my code so far:

for i=1:201

    A=sum(J(:,i));
    B=i;
end
plot(B,A)

Answer 1

[Azzi Abdelmalek]

for i=1:201
  A(i)=sum(J(:,i));
  B(i)=i;
end
plot(B,A)

[A R]

Thank you very much! This has been bothering me for a while.

Answer 2

[James Tursa]

plot(1:size(J,2),sum(J));