How can I automate a process for n times?

So basically I have a working code to calculate some values from a Matrix.

My problem is that I had to input each one manually, and I think there most be a way to automate it so I can reduce the amount of code needed.

I'll show 2 instances in which I'd like to do this, (both of them I believe should have the same "solution")

As I said I use a Matrix

J = [14 0 0 0 0; 15 0 0 0 0; 16 16 16 0 0; 22 22 0 0 0; 24 24 0 0 0; 25 25 25 25 25]

Lr = length ( J(:,1) );

Then I extract each row individually the following way

r1 = J(1,:);
r2 = J(2,:);
r3 = J(3,:);
r4 = J(4,:);
r5 = J(5,:);
r6 = J(6,:);

Which is just not very efficient.

My idea of a solution would be something like this

for i = 1:Lr
    r(i) = J(i,:)
end

But that gives me the following error.

"Unable to perform assignment because the indices on the left side are not compatible with the size of the right side."

(Which to be fair, I'm not sure what it means or how to solve it)

I would like to find a way to automate this, and then later on being able to call each value, so each iteration saves itself and would allow me to use it later on, as I do here. (Which also needs to be automated)

nr1 = nnz(r1);
nr2 = nnz(r2);
nr3 = nnz(r3);
nr4 = nnz(r4);
nr5 = nnz(r5);
nr6 = nnz(r6);

Thank you so much if anyone reads all the way.

Answer 1

[Chunru]

J = [14 0 0 0 0; 15 0 0 0 0; 16 16 16 0 0; 22 22 0 0 0; 24 24 0 0 0; 25 25 25 25 25]

J = 6×5

14 0 0 0 0 15 0 0 0 0 16 16 16 0 0 22 22 0 0 0 24 24 0 0 0 25 25 25 25 25

Lr = size(J,1);
for i = 1:Lr
    row = J(i,:);
    % Do something with row below
    a = sum(row)
end

a = 14

a = 15

a = 48

a = 44

a = 48

a = 125

[Mikel Gonzalez Bribiesca]

Thank you so much!

Do you know a way for it to save each iteration?

for i = 1:Lr
    row(i) = J(i,:);
end

Something along those lines

[Walter Roberson]

for i = 1:Lr
    row(i,:) = J(i,:);
end

But that is the same as

row(1:Lr,:) = J(1:Lr,:);

and when Lr is the number of rows in J like you have in your code, that simplifies to

row = J;

[Mikel Gonzalez Bribiesca]

Thank you, yes that works! Crazy how simple you make it