This writes a 3D matrix to a VTK file. An old text-based format is used because it is easy to write to. This may result in very large file sizes.
The matrix is normalised, kind of. Not sure why I did that; it might not be needed. The code is very short so feel free to experiment!
m = reshape(magic(6), [3 3 4]);
thanks for your code.
I met a problem in useing it
v = round(100 .* v(:) ./ mx);
The data format of I used is decimal，so I modified the code.
v = 100 .* v(:) ./ 100;
But the result is not correct.
Could you give some help?
Thanks for your code, it is really helpful.
Actually, i just modified the file to be more general to scalar data, using signed, floating points. No need to normalize, no need to have positive values :
For that, one can simply change " SCALARS blah char "
to "SCALARS blah float".
Then instead of :
use, for instance with a precision of 3 digits :
which will add only one blank space between each value whether it is positive or negative. (fwrite would actually add 2 blanks if the value is positive, fprintf understands the \040 ascii code as it's supposed to).
So, finally, we'd have :
fwrite(fid, ['# vtk DataFile Version 2.0' nl 'Volume example' nl 'ASCII' nl ...
'DATASET STRUCTURED_POINTS' nl 'DIMENSIONS ' ...
num2str(N) ' ' num2str(M) ' ' num2str(O) nl 'ASPECT_RATIO 1 1 1' nl ...
'ORIGIN 0 0 0' nl 'POINT_DATA ' ...
num2str(N*M*O) nl 'SCALARS matlab_scalars float 1' nl 'LOOKUP_TABLE default' nl]);
for z = 1:O
% Get this layer.
v = matrix(:, :, z)';
% Scale it. This assumes there are no negative numbers. I'm not sure
% this is actually necessary.
v = v(:)';
% Write the values as text numbers.
Tested with Paraview 4.1. Worked like charm.
According to your code, one should be careful as for the X and Y dimension. VTK structured data have x coordinates increasing faster, then y, and z.
By doing v = matrix(:, :, z);, the Y coordinates (rows) increase faster. Thus the VTK reader will assimilate the rows as the X dimension. So unless we transpose the matrix before sending it to writeToVTK, the VTK reader (paraview) will show us a transposed version of our arrays, X/Y -> Y/X. Am i correct ?
Good for export to VTK of matrices only.
Awesome! Great for viewing 3-D level-set data...and then making quick stereo movies in paraview..thanks Tim.
View the winning live scripts from faculty and students who participated in the recent challenge.Learn more
Download apps, toolboxes, and other File Exchange content using Add-On Explorer in MATLAB.