how to append a matrix with a nested for loop?

Hello,

I have a nested for loop where I want to append the matrix for every for loop.

subjs = {'subj1' 'subj2'}
experiments = {'groundtruth' 'change1' 'change2'} 
percent_change_matrix = [] %preallocating
percent_change_control_matrix = []
 
for s = 1:length(subjs) 
    subj = subjs{s}
for i = 1:length(experiments)
    experiment = experiments{i}
     
data = load(fullfile('text.txt']))
data = data(:,5)
data(:,i)=data

task(:,i) = data(5,5)
baseline(:,i) = data(5,5)
percent_change(:,i) = ((task-baseline)/baseline)*100

end

percent_change_matrix = [percent_change_matrix; percent_change]

end

where I want my output matrix to look as follows:

groundtruth change1 change2

subj 1 0 10 12

subj2 0 10 12

when right now my output looks like this:

0

0

10

12

0

12

Do you have any suggestions?

Thanks

Answer 1

[NIVEDITA MAJEE]

Hello,

Please take a look at the following documentation for expanding matrices:

https://in.mathworks.com/help/matlab/math/creating-and-concatenating-matrices.html#:~:text=You%20can%20add%20one%20or,(3%2C4)%20position.

You can also take a look at this MATLAB answer:

https://in.mathworks.com/matlabcentral/answers/113813-append-rows-at-the-end-of-matrix

Hope this helps!