writePetscBin_DKE_ft

 USAGE: writePetscBin(filename,X,multiVec,isBig)
 Function to write a vector or matrix to PETSc binary format
 INPUTS:
  filename: name of file to write vector/matrix to
  X: vector or sparse matrix
  multiVec: If X has more than one column, multiVec=1 
            indicates that X each column of X is a 
            vector.
  isBig: flag to force script to call a mex function when 
         writing out a sparse matrix. Use this option for 
         large matrices.
         To use this option you must have the mex function 
         'writePetscBinaryMat_mex.mexXXX' in your path.
 Samar Khatiwala (spk@ldeo.columbia.edu)
 This function is based on code originally written by Antti.Vanne@uku.fi

0001 function writePetscBin(filename,X,multiVec,isBig)
0002 
0003 % USAGE: writePetscBin(filename,X,multiVec,isBig)
0004 % Function to write a vector or matrix to PETSc binary format
0005 % INPUTS:
0006 %  filename: name of file to write vector/matrix to
0007 %  X: vector or sparse matrix
0008 %  multiVec: If X has more than one column, multiVec=1
0009 %            indicates that X each column of X is a
0010 %            vector.
0011 %  isBig: flag to force script to call a mex function when
0012 %         writing out a sparse matrix. Use this option for
0013 %         large matrices.
0014 %         To use this option you must have the mex function
0015 %         'writePetscBinaryMat_mex.mexXXX' in your path.
0016 % Samar Khatiwala (spk@ldeo.columbia.edu)
0017 % This function is based on code originally written by Antti.Vanne@uku.fi
0018 
0019 if nargin<3
0020   multiVec=0;
0021 end
0022 if isempty(multiVec)
0023   multiVec=0;
0024 end
0025 
0026 if nargin<4
0027   isBig=0;
0028 end
0029 if isempty(isBig)
0030   isBig=0;
0031 end
0032 
0033 MAT_FILE_COOKIE=1211216;
0034 VEC_FILE_COOKIE=1211214;
0035 
0036 if (size(X,2) == 1) || (multiVec==1) 
0037     if ~isBig
0038 % X is a vector
0039 %  disp('Saving vector..');
0040   fid=fopen(filename,'w','ieee-be');  
0041   nv=size(X,2);
0042   for it=1:nv
0043     fwrite(fid,VEC_FILE_COOKIE,'int');
0044     fwrite(fid,size(X,1),'int');
0045     fwrite(fid,full(X(:,it)),'float64');
0046   end
0047   fclose(fid);
0048 %  disp(['Wrote ' num2str(nv) ' vectors'])
0049  
0050     else
0051 %    disp('using mexfile')
0052     writePetscBinaryVec_mex_c(filename,X');
0053 end
0054 else 
0055 % X is a matrix
0056 %  disp('Saving matrix');
0057   if ~isBig
0058     fid=fopen(filename,'w','ieee-be');
0059     [M,N]=size(X);
0060     fwrite(fid,MAT_FILE_COOKIE,'int');
0061     fwrite(fid,M,'int');
0062     fwrite(fid,N,'int');
0063     fwrite(fid,nnz(X),'int');
0064     [ii,jj,aa]=find(X');
0065 % nonzeros in each row
0066     nnzrow=zeros(size(X,1), 1);
0067 %    for kk = 1:M
0068 %       nnzrow(kk) = nnz(jj==kk); % slow
0069 %       nnzrow(kk) = length(find(jj==kk)); % faster
0070 %    end
0071     nnzrow(:)=full(sum(spones(X'))'); % fastest
0072     fwrite(fid,nnzrow,'int');
0073     fwrite(fid,ii-1,'int');
0074     fwrite(fid,aa,'float64');
0075   else
0076 %      disp('using mexfile')
0077     writePetscBinaryMat_mex_c(filename,X')
0078   end
0079 end