How to save output in different column for each loop

I was trying to save the output from each for loop into the different column using fprintf(fid,'%7.4f %7.4f %7.4f %7.4f\n',A). I want the first run to complete and save output, and have the second run and save it into different column. However, it is not saving output into four different column rather saving out in a single one. Any suggestion?

Answer 1

[jean claude]

you have to design the dimension of your output matrix, example if it is 10x3 set i(number of rows) and j(number of columns), than for loop will begin like loop#1 i=1 j=1 loop#2 i=1 j=2 loop#3 i=1 j=3 then loop#4 i=2 j=1 loop#5 i=2 j=2 loop#6 i=2 j=3 ...etc

for i=1:10
    for j=1:3

       x=randn(1);
       a(i,j)=x ;
      end
  end

you can always use debugging mode https://www.mathworks.com/help/matlab/matlab_prog/debugging-process-and-features.html to understand how matlab treat your loop

Answer 2

[Fangjun Jiang]

You could save the result in a temporary variable and do fprintf() at once. For example

A=zeros(4,1);
for k=1:4
A(k,1)=k+rand(1);
end
fprintf(1,'%7.4f %7.4f %7.4f %7.4f\n',A);