MATLAB: save 高精度csv文件

fjing = [];
for i = 1: size(data_fenzu_new_x,2)-1
    fjing = [fjing, '%.8f,'];
end
fjing = [fjing, '%.8f\n'];

fid=fopen('data_fenzu_new_x.csv','w')   %  16th_data_chazhi3.csv 为固定精度的数据
% fid=fopen('16th_data_chazhi2.txt','w')
for i=1:size(data_fenzu_new_x,1)
    fprintf(fid,fjing,data_fenzu_new_x(i,1:size(data_fenzu_new_x,2)));
end
fclose(fid)