How can I append matrix in loop?

I made the code below

fileid = fopen('test.txt' , 'w');

a = rand(2,2,2);

fileid = fopen('test.txt' , 'w');

for i = 1:2

fprintf(fileid,num2str(i));
fprintf(fileid,'\n');

dlmwrite('test.txt',a(:,:,i),'-append','delimiter',' ');

end

So the result like that

1

2

95751 0.15761

0.96489 0.97059

0.95717 0.80028

0.48538 0.14189

I want a append immediately after i like that

1

95751 0.15761

0.96489 0.97059

2

0.95717 0.80028

0.48538 0.14189

Any one can help me solve this problem?

Thanks

Answer 1

[Walter Roberson]

a = rand(2,2,2);

for i = 1:2

    fileid = fopen('test.txt' , 'a');
    fprintf(fileid,num2str(i));
    fprintf(fileid,'\n');
    fclose(fileid);

    dlmwrite('test.txt',a(:,:,i),'-append','delimiter',' ');

end

The dlmwrite() will not happen properly if you have the file open for writing.