function hexvtkwrite(base_path,filename,MESH,V, point_data, cell_data, opt)
%vtkwrite 此处显示有关此函数的摘要
%   此处显示详细说明

%   Write Paraview VTK Hex File
%   Author: Hu Xinzhuo
%   Create Time: 2021-01-11
%   Update Time: 2021-01-11

% MESH: num_elems X 8
%    V: num_nodes X 3

num_ele=size(MESH,1);
num_nod=size(V,1);

MESH = MESH-1; % vtk从0开始编号
OUTP2 = [8.*ones(num_ele,1),MESH];

vtkf = [filename,'.vtk'];
myfile = fullfile(base_path,vtkf);
fileID = fopen(myfile,'w');

fprintf(fileID,'# vtk DataFile Version 3.0\n');
fprintf(fileID,'Volume Mesh\n');
fprintf(fileID,'ASCII\n');
fprintf(fileID,'DATASET UNSTRUCTURED_GRID\n');

fprintf(fileID,'POINTS %d double\n',num_nod);
fprintf(fileID,'%f %f %f \n',V.');

fprintf(fileID,'CELLS %d %d\n',num_ele,num_ele*(8+1));
fprintf(fileID,'%d %d %d %d %d %d %d %d %d\n',OUTP2.');

fprintf(fileID,'CELL_TYPES %d\n',num_ele);
fprintf(fileID,'%d\n',12.*ones(num_ele,1));
% 10 for tet mesh; 12 for hex mesh

switch opt
    
    case 'POINT_DATA'
        
        fprintf(fileID,'POINT_DATA %d\n',num_nod);
        fprintf(fileID,'SCALARS point_scalars float 1\n');
        fprintf(fileID,'LOOKUP_TABLE default\n');
        fprintf(fileID,'%d\n',point_data);
        
    case 'CELL_DATA'
        
        fprintf(fileID,'CELL_DATA %d\n',num_ele);
        fprintf(fileID,'SCALARS cell_scalars float 1\n');
        fprintf(fileID,'LOOKUP_TABLE default\n');
        fprintf(fileID,'%d\n',cell_data);
        
    case 'ALL'
        
        % POINT_DATA
        fprintf(fileID,'POINT_DATA %d\n',num_nod);
        fprintf(fileID,'SCALARS point_scalars float 1\n');
        fprintf(fileID,'LOOKUP_TABLE default\n');
        fprintf(fileID,'%d\n',point_data);
        
        % CELL_DATA
        fprintf(fileID,'CELL_DATA %d\n',num_ele);
        fprintf(fileID,'SCALARS cell_scalars float 1\n');
        fprintf(fileID,'LOOKUP_TABLE default\n');
        fprintf(fileID,'%d\n',cell_data);
        
    case 'None'
        fclose(fileID);
        return;
    
end

fclose(fileID);

end