How to save the value of some variables in a .dat file inside a nested loop in the function environment

Hello everyone,

I am trying to create a .dat file on each for loop of a function enviroment file. The code looks like:

for i=1:length(Tmax0)
    for j=1:length(Hy0)
        [t,x]=ode45(@(t,x)myode(t,x,Hy0(j),Tmax0(i)),ts,[0 0]);
        LX=cos(x(:,1));
        LY=sin(x(:,1));
        TIME=t;
        TT=TEMP(t,Tmax0(i));
        mm=(1-TT/Tc).^beta;
        wwE=wE0*mm;
        MZ=-(1./(2.*wwE)).*x(:,2);
        % SAVE DATA HERE
    end
end

So what I want to save has to be done where the warning "% SAVE DATA HERE" is placed in the code. I would like to save on each file the value of TIME, LX, LY, and MZ as column vectors, for each iteration on the for loop on j=1:length(Hy0) for all the i=1:length(Tmax0) iterations. It would be great if the name of my file could be controled showing the value of Tmax0(i) and Hy0(j) like... "Laser_Like_Hy0=,'value(Hy0(j))',_Tmax0=,'value(Tmax0(i))'.dat". It would be great if all the decimals of the above variables are saved. Again, just in case that it is important, this code is inside a function environment. I do not if cell2mat works there, for example.

Any suggestions?

Answer 1

[Stephen23]

Replace "Save Data Here" with:

fnm = sprintf('Laser_Like_Hy0=%.12f_Tmax0=%.12f.dat', Hy0(j), Tmax0(i));
mat = [TIME(:), LX(:), LY(:), MZ(:)];
csvwrite(fnm,mat)

[Roderick]

Hey! Thank you very much for your answer! It worked perfectly. Just a final question. The data is separated with commas, is this suitable to be read by MatLab in other script or I should change the commas by space? If that it is the case, what should I change on your approach to incorporate that?

[Stephen23]

"The data is separated with commas, is this suitable to be read by MatLab in other script"

Yes, a comma-separated file can be trivially imported into MATLAB using csvread.

Comma-separated files are a very common format for storing data in a text file:

https://en.wikipedia.org/wiki/Comma-separated_values

If you want to export/import data using a space delimiter, then use dlmwrite and dlmread.

Please remember to accept my answer if it helped you to resolve your original question.

[Roderick]

Done. Thank you for your comments!