CODEWITHSUNDEEP
matlabcsv
user3600497
user3600497

Reputation: 1661

How can I write a csv line by line?

I am performing a simulation many many times, and would like to store the result in a csv file.

I could just save the results in an array and write the array to a csv, but the array would be very large and a big strain on my system.

I was thinking it could be easier to simulate, save the result of one simulation in a csv, complete a new simulation, and then store the new result in the second line of the csv.

How can I write csv lines one by one in matlab?

Upvotes: 1

Views: 3314

Answers (2)

Corax
Corax

Reputation: 41

Easy, use: dlmwrite(filename,M,'-append')

For example:

simulation_results = [1,2,3,4]

dlmwrite('C:\<Your Directory Path>\simulaton_results.csv', simulation_results, '-append');

This will append the simulation_results matrix to the end of the file you specify. The default delimiter is a comma ... perfect for writing csv files.

Upvotes: 4

mike
mike

Reputation: 173

Try fprintf

%save to file
%save using fprintf function

fid_out = fopen('file_out.csv','w'); %open file and create fid

%save tab-separated column headers
%define column format and names and save to file
fprintf(fid_out,'%s\t%s\t%s\t%s\n','a_name','b_name','c_name','d_name');

%save tab-separated columns of data
for i = 1:size(data,1) %loop trough each line of each data variable and save to file line by line

%define column format and date to be saved.
%use () for numeric data, and {} for strings
fprintf(fid_out,'%s\t%s\t%d\t%.5f\n',a{i},b{i},c(i),d(i));
end

fclose(fid_out); %close file

%NOTE: fprintf cannot save structured data

Upvotes: 1

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