How to save 3D data in text file?

I am trying to print my 3D data in a text file so I can perform some postprocessing. The form of my 3D data is the following:

%size Nx x Ny x Nz double

val(:,:,1) =

   1.0e-03 *

   -0.1330   -0.0709    0.1597    0.1604   -0.0717   -0.1323   -0.0717    0.1604    0.1597   -0.0709
   -0.1298   -0.0725    0.1376    0.1380   -0.0730   -0.1294   -0.0730    0.1380    0.1376   -0.0725
   -0.1158   -0.0565    0.1374    0.1377   -0.0567   -0.1155   -0.0567    0.1377    0.1374   -0.0565
   -0.0752   -0.0363    0.0748    0.0748   -0.0363   -0.0752   -0.0363    0.0748    0.0748   -0.0363
   -0.0355   -0.0119    0.0498    0.0498   -0.0120   -0.0355   -0.0120    0.0498    0.0498   -0.0119
   -0.0077   -0.0028    0.0033    0.0033   -0.0028   -0.0077   -0.0028    0.0033    0.0033   -0.0028
   -0.0041    0.0029    0.0171    0.0171    0.0029   -0.0041    0.0029    0.0171    0.0171    0.0029
   -0.0112   -0.0058    0.0076    0.0076   -0.0058   -0.0112   -0.0058    0.0076    0.0076   -0.0058
   -0.0237   -0.0086    0.0398    0.0399   -0.0087   -0.0236   -0.0087    0.0399    0.0398   -0.0086
   -0.0272   -0.0167    0.0272    0.0273   -0.0168   -0.0271   -0.0168    0.0273    0.0272   -0.0167
   -0.0291   -0.0132    0.0472    0.0474   -0.0134   -0.0288   -0.0134    0.0474    0.0472   -0.0132


val(:,:,2) =
...

How can I write this to text file?

Answer 1

[KSSV]

m = 4; n = 3 ; p = 4 ; % dimensions for matrix 
A = rand(m,n,p);  % make a dummy 3d matrix 
F = [repmat(' %0.4f',1,n),'\n'];  % make the required format 
fid = fopen('test.txt','w') ;  % open file to write 
% loop to write each 2D matrix 
for i = 1:p    
    fprintf(fid,F,A(:,:,i).') ;  % write the p'th matrix 
    fprintf(fid,'\n') ;  % give empty space after a matrix is written
end