Matlab处理数据导出Paraview可读的vtk文件（一）

Paraview是一个开源的可视化软件。

用到matlab子程序从这里下载

或者到博客末尾复制粘贴

子程序名为 vtkwrite

示例1：

 load mri
 D = squeeze(D);
 vtkwrite('mri.vtk', 'structured_points', 'mri', D) 

示例2：云图

 load wind
 [cu,cv,cw] = curl(x, y, z, u, v, w);
 div = divergence(x, y, z, u, v, w);
 vtkwrite('wind.vtk', 'structured_grid', x, y, z, ...
 'vectors', 'vector_field', u, v, w, 'vectors', 'vorticity', cu, cv, cw, 'scalars', 'divergence', div);

示例3：二维曲线

 x = :;
 y = sin(x);
 z = sqrt(x);
 vtkwrite('execute','polydata','lines',x,y,z); 

示例4：三角形

 [x,y,z] = peaks();
 z = .*z;
 tri = delaunay(x,y);
 vtkwrite('peaks.vtk','polydata','triangle',x,y,z,tri); 

示例5：四面体

 d = [- ];
 [x, y, z] = meshgrid(d, d, d);
 DT = delaunayTriangulation(x(:), y(:), z(:));
 vtkwrite('execute', 'polydata','tetrahedron', x, y, z, DT.ConnectivityList);  

vtkwrite

 function vtkwrite( filename,dataType,varargin )
 % VTKWRITE Writes 3D Matlab array into VTK file format.
 %  vtkwrite(filename,'structured_grid',x,y,z,'vectors',title,u,v,w) writes
 %  a structured 3D vector data into VTK file, with name specified by the string
 %  filename. (u,v,w) are the vector components at the points (x,y,z). x,y,z
 %  should be -D matrices like those generated by meshgrid, where
 %  point(ijk) is specified by x(i,j,k), y(i,j,k) and z(i,j,k).
 %  The matrices x,y,z,u,v,w must all be the same size and contain
 %  corrresponding position and vector component. The string title specifies
 %  the name of the vector field to be saved.
 %
 %  vtkwrite(filename,'structured_grid',x,y,z,'scalars',title,r) writes a 3D
 %  scalar data into VTK file whose name is specified by the string
 %  filename. r is the scalar value at the points (x,y,z). The matrices
 %  x,y,z,r must all be the same size and contain the corresponding position
 %  and scalar values.
 %
 %  vtkwrite(filename,'structured_grid',x,y,z,'vectors',title,u,v,w,'scalars',
 %  title2,r) writes a 3D structured grid that contains both vector and scalar values.
 %  x,y,z,u,v,w,r must all be the same size and contain the corresponding
 %  positon, vector and scalar values.
 %
 %  vtkwrite(filename, 'structured_points', title, m) saves matrix m (could
 %  be 1D, 2D or 3D array) into vtk as structured points.
 %
 %  vtkwrite(filename, 'structured_points', title, m, 'spacing', sx, sy, sz)
 %  allows user to specify spacing. (default: , , ). This is the aspect
 %  ratio of a single voxel.
 %
 %  vtkwrite(filename, 'structured_points', title, m, 'origin', ox, oy, oz)
 %  allows user to speicify origin of dataset. (default: , , ).
 %
 %  vtkwrite(filename,'unstructured_grid',x,y,z,'vectors',title,u,v,w,'scalars',
 %  title2,r) writes a 3D unstructured grid that contains both vector and scalar values.
 %  x,y,z,u,v,w,r must all be the same size and contain the corresponding
 %  positon, vector and scalar values.
 %
 %  vtkwrite(filename, 'polydata', 'lines', x, y, z) exports a 3D line where
 %  x,y,z are coordinates of the points that make the line. x, y, z are
 %  vectors containing the coordinates of points of the line, where point(n)
 %  is specified by x(n), y(n) and z(n).
 %
 %  vtkwrite(filename,'polydata','lines',x,y,z,'Precision',n) allows you to
 %  specify precision of the exported number up to n digits after decimal
 %  point. Default precision is  digits.
 %
 %  vtkwrite(filename,'polydata','triangle',x,y,z,tri) exports a list of
 %  triangles where x,y,z are the coordinates of the points and tri is an
 %  m* matrix whose rows denote the points of the individual triangles.
 %
 %  vtkwrite(filename,'polydata','tetrahedron',x,y,z,tetra) exports a list
 %  of tetrahedrons where x,y,z are the coordinates of the points
 %  and tetra is an m* matrix whose rows denote the points of individual
 %  tetrahedrons.
 %
 %  vtkwrite('execute','polydata','lines',x,y,z) will save data with default
 %  filename ''matlab_export.vtk' and automatically loads data into
 %  ParaView.
 %
 %  Version 2.3
 %  Copyright, Chaoyuan Yeh,
 %  Codes are modified from William Thielicke and David Gingras's submission.    

 if strcmpi(filename,'execute'), filename = 'matlab_export.vtk'; end
 fid = fopen(filename, 'w');
 % VTK files contain five major parts
 % . VTK DataFile Version
 fprintf(fid, '# vtk DataFile Version 2.0\n');
 % . Title
 fprintf(fid, 'VTK from Matlab\n');

 binaryflag = any(strcmpi(varargin, 'BINARY'));
 if any(strcmpi(varargin, 'PRECISION'))
     precision = num2str(varargin{find(strcmpi(vin, 'PRECISION'))+});
 else
     precision = '';
 end

 switch upper(dataType)
     case 'STRUCTURED_POINTS'
         title = varargin{};
         m = varargin{};
         if any(strcmpi(varargin, 'spacing'))
             sx = varargin{find(strcmpi(varargin, 'spacing'))+};
             sy = varargin{find(strcmpi(varargin, 'spacing'))+};
             sz = varargin{find(strcmpi(varargin, 'spacing'))+};
         else
             sx = ;
             sy = ;
             sz = ;
         end
         if any(strcmpi(varargin, 'origin'))
             ox = varargin{find(strcmpi(varargin, 'origin'))+};
             oy = varargin{find(strcmpi(varargin, 'origin'))+};
             oz = varargin{find(strcmpi(varargin, 'origin'))+};
         else
             ox = ;
             oy = ;
             oz = ;
         end
         [nx, ny, nz] = size(m);
         setdataformat(fid, binaryflag);

         fprintf(fid, 'DATASET STRUCTURED_POINTS\n');
         fprintf(fid, 'DIMENSIONS %d %d %d\n', nx, ny, nz);
         fprintf(fid, ['SPACING ', num2str(sx), ' ', num2str(sy), ' ',...
             num2str(sz), '\n']);
         fprintf(fid, ['ORIGIN ', num2str(ox), ' ', num2str(oy), ' ',...
             num2str(oz), '\n']);
         fprintf(fid, 'POINT_DATA %d\n', nx*ny*nz);
         fprintf(fid, ['SCALARS ', title, ' float 1\n']);
         fprintf(fid,'LOOKUP_TABLE default\n');
         if ~binaryflag
             spec = ['%0.', precision, 'f '];
             fprintf(fid, spec, m(:)');
         else
             fwrite(fid, m(:)', 'float', 'b');
         end

     case {'STRUCTURED_GRID','UNSTRUCTURED_GRID'}
         % . The format data proper is saved in (ASCII or Binary). Use
         % fprintf to write data in the case of ASCII and fwrite for binary.
         if numel(varargin)<, error('Not enough input arguments'); end
         setdataformat(fid, binaryflag);
 %         fprintf(fid, 'BINARY\n');
         x = varargin{};
         y = varargin{};
         z = varargin{};
         if sum(size(x)==size(y) & size(y)==size(z))~=length(size(x))
             error('Input dimesions do not match')
         end
         n_elements = numel(x);
         % . Type of Dataset ( can be STRUCTURED_POINTS, STRUCTURED_GRID,
         % UNSTRUCTURED_GRID, POLYDATA, RECTILINEAR_GRID or FIELD )
         % This part, dataset structure, begins with a line containing the
         % keyword 'DATASET' followed by a keyword describing the type of dataset.
         % Then the geomettry part describes geometry and topology of the dataset.
         if strcmpi(dataType,'STRUCTURED_GRID')
             fprintf(fid, 'DATASET STRUCTURED_GRID\n');
             fprintf(fid, 'DIMENSIONS %d %d %d\n', size(x,), size(x,), size(x,));
         else
             fprintf(fid, 'DATASET UNSTRUCTURED_GRID\n');
         end
         fprintf(fid, ['POINTS ' num2str(n_elements) ' float\n']);
         output = [x(:)'; y(:)'; z(:)'];

         if ~binaryflag
             spec = ['%0.', precision, 'f '];
             fprintf(fid, spec, output);
         else
             fwrite(fid, output, 'float', 'b');
         end
         % .This final part describe the dataset attributes and begins with the
         % keywords 'POINT_DATA' or 'CELL_DATA', followed by an integer number
         % specifying the number of points of cells. Other keyword/data combination
         % then define the actual dataset attribute values.
         fprintf(fid, ['\nPOINT_DATA ' num2str(n_elements)]);
         % Parse remaining argument.
         vidx = find(strcmpi(varargin,'VECTORS'));
         sidx = find(strcmpi(varargin,'SCALARS'));
         if vidx~=
             for ii = :length(vidx)
                 title = varargin{vidx(ii)+};
                 % Data enteries begin with a keyword specifying data type
                 % and numeric format.
                 fprintf(fid, ['\nVECTORS ', title,' float\n']);
                 output = [varargin{ vidx(ii) +  }(:)';...
                           varargin{ vidx(ii) +  }(:)';...
                           varargin{ vidx(ii) +  }(:)'];

                 if ~binaryflag
                     spec = ['%0.', precision, 'f '];
                     fprintf(fid, spec, output);
                 else
                     fwrite(fid, output, 'float', 'b');
                 end
 %                 fwrite(fid, [reshape(varargin{vidx(ii)+},,n_elements);...
 %                 reshape(varargin{vidx(ii)+},,n_elements);...
 %                 reshape(varargin{vidx(ii)+},,n_elements)],'float','b');
             end
         end
         if sidx~=
             for ii = :length(sidx)
                 title = varargin{sidx(ii)+};
                 fprintf(fid, ['\nSCALARS ', title,' float\n']);
                 fprintf(fid, 'LOOKUP_TABLE default\n');
                 if ~binaryflag
                     spec = ['%0.', precision, 'f '];
                     fprintf(fid, spec, varargin{ sidx(ii) + });
                 else
                     fwrite(fid, varargin{ sidx(ii) + }, 'float', 'b');
                 end
 %                 fwrite(fid, reshape(varargin{sidx(ii)+},,n_elements),'float','b');
             end
         end

     case 'POLYDATA'

         fprintf(fid, 'ASCII\n');
         if numel(varargin)<, error('Not enough input arguments'); end
         x = varargin{}(:);
         y = varargin{}(:);
         z = varargin{}(:);
         if numel(varargin)<, error('Not enough input arguments'); end
         if sum(size(x)==size(y) & size(y)==size(z))~= length(size(x))
             error('Input dimesions do not match')
         end
         n_elements = numel(x);
         fprintf(fid, 'DATASET POLYDATA\n');
         if mod(n_elements,)==
             x(n_elements+:n_elements+,)=[;];
             y(n_elements+:n_elements+,)=[;];
             z(n_elements+:n_elements+,)=[;];
         elseif mod(n_elements,)==
             x(n_elements+,)=;
             y(n_elements+,)=;
             z(n_elements+,)=;
         end
         nbpoint = numel(x);
         fprintf(fid, ['POINTS ' num2str(nbpoint) ' float\n']);

         spec = [repmat(['%0.', precision, 'f '], , ), '\n'];

         output = [x(::end-), y(::end-), z(::end-),...
                   x(::end-), y(::end-), z(::end-),...
                   x(::end), y(::end), z(::end)]';

         fprintf(fid, spec, output);

         switch upper(varargin{})
             case 'LINES'
                 if mod(n_elements,)==
                     nbLine = *n_elements-;
                 else
                     nbLine = *(n_elements-);
                 end
                 conn1 = zeros(nbLine,);
                 conn2 = zeros(nbLine,);
                 conn2(:nbLine/) = :nbLine/;
                 conn1(:nbLine/) = conn2(:nbLine/)-;
                 conn1(nbLine/+:end) = :nbLine/;
                 conn2(nbLine/+:end) = conn1(nbLine/+:end)-;
                 fprintf(fid,'\nLINES %d %d\n',nbLine,*nbLine);
                 fprintf(fid,'2 %d %d\n',[conn1';conn2']);
             case 'TRIANGLE'
                 ntri = length(varargin{});
                 fprintf(fid,'\nPOLYGONS %d %d\n',ntri,*ntri);
                 fprintf(fid,'3 %d %d %d\n',(varargin{}-)');
             case 'TETRAHEDRON'
                 ntetra = length(varargin{});
                 fprintf(fid,'\nPOLYGONS %d %d\n',ntetra,*ntetra);
                 fprintf(fid,'4 %d %d %d %d\n',(varargin{}-)');
         end
 end
 fclose(fid);
 if strcmpi(filename,'matlab_export.vtk')
     switch computer
         case {'PCWIN','PCWIN64'}
             !paraview.exe --data='matlab_export.vtk' &
             % Exclamation point character is a shell escape, the rest of the
             % input line will be sent to operating system. It can not take
             % variables, though. The & at the end of line will return control to
             % Matlab even when the outside process is still running.
         case {'GLNXA64','MACI64'}
             !paraview --data='matlab_export.vtk' &
     end
 end
 end

 function setdataformat(fid, binaryflag)

 if ~binaryflag
     fprintf(fid, 'ASCII\n');
 else
     fprintf(fid, 'BINARY\n');
 end
 end