sum of all matrix elements equal to zero

Hi, kindly check the code. I want a matrix whose total sum of elements is zero.......

regards

clc
clear all
format compact

nrows = 5
afm_array = ones(nrows)

theta = round((rand(5)-0.5) * 360)

theta(5,5) = 0
alpha = sum(sum(theta))-360
theta(5,5) =  - alpha
theta_new = theta
add_theta = sum(sum(theta_new))

Answer 1

[John D'Errico]

Well, you COULD just subtract off the sum of the matrix, divided by the number of elements in the matrix.

theta = theta - sum(theta(:))/numel(theta);

That is actually not a terribly good way to solve the problem, for reasons I don't feel like going into here, because it will take a lot of explanation. Just accept it works, but is not the best solution.

Better would be to use a tool like randfixedsum, from the file exchange.