This code works perfectly. To check it add the following at the very end of the above code:
fid = fopen('Mymatrix.txt','r');
[A1,n]=fscanf(fid,'%g %g',[7 inf]);
fclose(fid);
fprintf(1,'Data being fed from the file is :\n')
A1'
and compare A1 with (the original data) A.