Output numeric matrix to csv with a header

Courtesy of http://www.squaregoldfish.co.uk/2010/04/11/writing-csv-files-with-headers-in-matlab/

header=['test 1, test 2, test 3'];
outid = fopen(‘out.csv’, ‘w+’);
fprintf(outid, ‘%s’, header);
fclose(outid);
dlmwrite (‘out.csv’,csvData,’roffset’,1,’-append’)