For loop: saving variables for each iteration

Hi,

I am just starting using MatLab, so please accept my apologies if this question sounds very stupid or easy. I have tried reading many questions that seemed related but did not find the solution to my problem (or at least I didn't recognise it as such).

I am creating an experiment (using Psychtoolbox) that uses a for loop. Within this loop there is a random permutation of an array. What I would like to do is obtaining, at the end of the loop, a matrix/xls file/csv file showing in consecutive lines the value of the permutation for each iteration of the loop.

My script looks like this:

 for j = 1:4  

     AvailableTrials = [1 2 3 4];
     ATsize = numel(AvailableTrials);
     MyTrial = AvailableTrials(randperm(ATsize, 1))  

     if MyTrial == 1
        runscriptone; % these are other scripts already present in the same directory

     elseif MyTrial == 2
        runscripttwo;    

     else
        runscriptthree;   

     end  
 end

I would like my output to look something like this:

j . MyTrial

1 . 2

2 . 4

3 . 1

4 . 2

5 . 3

6 . 1

etc

I hope this makes sense and that somebody will be able to help me. Thank you!

Answer 1

[Fangjun Jiang]

Add a few lines to create your desired output in a text file.

fid=fopen('output.txt','w+t');
fprintf(fid,'j . MyTrial\n');
for j = 1:4  
     AvailableTrials = [1 2 3 4];
     ATsize = numel(AvailableTrials);
     MyTrial = AvailableTrials(randperm(ATsize, 1))  
     if MyTrial == 1
        runscriptone; % these are other scripts already present in the same directory
     elseif MyTrial == 2
        runscripttwo;    
     else
        runscriptthree;   
     end  
     fprintf(fid,'%d . %d\n',j,MyTrial);
 end      
fclose(fid);

[Giulia Orioli]

Hi Fangjun, thank you for your answer. This works, but records only the information for the last trial, not for all of them.

[Fangjun Jiang]

There is one typo. In the last fprintf() line, the loop variable should be j (instead of i previously). However, if you've figured this out already, I thought the output was right, like below

j . MyTrial
1 . 4
2 . 1
3 . 3
4 . 2