How to print a 3D matrix to a text file?

How can I save the following 3D matrix in a text file using MATLAB?

Nx = 4;
Ny = 4;  
Nz = 4;
x   = (0:Nx-1)/Nx*2*pi;         
y   = (0:Ny-1)/Ny*2*pi;
z   = (0:Nz-1)/Nz*2*pi;
[X,Y,Z] = meshgrid(x,y,z);
%how to save X, Y, and Z in text files?

[Dyuman Joshi]

You can directly write a matrix into a text file using writematrix()

Nx = 4;
Ny = 4;  
Nz = 4;
x   = (0:Nx-1)/Nx*2*pi;         
y   = (0:Ny-1)/Ny*2*pi;
z   = (0:Nz-1)/Nz*2*pi;
[X,Y,Z] = meshgrid(x,y,z);
%how to save X, Y, and Z in text files?
X

X = 
X(:,:,1) =

         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124


X(:,:,2) =

         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124


X(:,:,3) =

         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124


X(:,:,4) =

         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124
         0    1.5708    3.1416    4.7124

%writing in a text file
writematrix(X,'X.txt')
%showing the output
type 'X.txt'

0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469
0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469
0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469
0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469,0,1.5707963267949,3.14159265358979,4.71238898038469

However, is this the way you want to store the matrix?

If not, please give an example of how you would want to store a matrix

[Jamie Al]

Thanks!

[Jamie Al]

Just noticed this prints a text file that is readable as 16X256 instead of 16x16x16 and I wonder if it has to do with the readmatrix function or the way it's written into a text file. Thanks again.

Answer 1

[Sailesh Kalyanapu]

As per my understanding, you are trying to save a 3D Matrix in a text file using MATLAB.

You could use writematrix() function to writes a homogeneous array to a comma delimited text file.

You can also refer to this MATLAB Answers post for saving a 3D matrix using MATLAB’s ‘save()’ function:

https://in.mathworks.com/matlabcentral/answers/46120-save-a-three-dimensional-matrix#answer_56399

For more information on ‘writematrix’ and ‘save’ functions, please refer to the below links to their respective documentations:

• https://in.mathworks.com/help/matlab/ref/save.html
• https://in.mathworks.com/help/matlab/ref/writematrix.html