function [] = write_scal_complete_ucf(file,s,ibegp,iendp,jbegp,jendp,kbegp,kendp,time,varargin)
    % [] = write_scal_complete_ucf(file,s,ibegp,iendp,jbegp,jendp,kbegp,kendp,time,varargin)
    % Writes a complete scalar field to UCF chunks.
    % Input
    %   file                file to be written (the extension will be replaced by the proc rank)
    %   s                   full scalar field with dim(nx,ny,nz,nscal)
    %   ibegp,jbegp,kbegp   arrays with length(n.proc) with processor grid
    %   iendp,jendp,kendp   """
    %   time                simulation time
    % Optional input (key/value pair)
    %   endian              endianess of the file as used by fopen (default: 'n')
    %   verbosity           verbose output? (default: no)
    %   debug               debug output? (default: no)

    % Parse variable input
    par = inputParser;
    addParamValue(par,'endian','n',@ischar);
    addParamValue(par,'verbosity',0,@isnumeric);
    addParamValue(par,'debug',0,@isnumeric);
    parse(par,varargin{:});

    % Parse filename
    [fdir,fbase,fext] = fileparts(file);
    fbasepath = fullfile(fdir,fbase);

    nxprocs = numel(ibegp);
    nyprocs = numel(jbegp);
    nzprocs = numel(kbegp);

    nx = size(s,1);
    ny = size(s,2);
    nz = size(s,3);
    nscal = size(s,4);

    for ixproc=0:nxprocs-1
      for iyproc=0:nyprocs-1
        for izproc=0:nzprocs-1
          [iproc] = locfun_proc_id(ixproc,iyproc,izproc,nxprocs,nyprocs,nzprocs);
          fname = sprintf('%s.%05d',fbasepath,iproc);

          % Extract local indices
          ighost = 0;
          ib = ibegp(ixproc+1);
          ie = iendp(ixproc+1);
          jb = jbegp(iyproc+1);
          je = jendp(iyproc+1);
          kb = kbegp(izproc+1);
          ke = kendp(izproc+1);
          nxl = ie-ib+1;
          nyl = je-jb+1;
          nzl = ke-kb+1;

          % Create a new chunk file
          obj = ucf('verbosity',par.Results.verbosity,'debug',par.Results.debug);
          obj.create(fname,'type','field','rank',[iproc,ixproc,iyproc,izproc],'endian',par.Results.endian);
          obj.appendStep(time);

          % Write data field by field
          for iscal=1:nscal
            params = int64([ighost,ib,jb,kb,nxl,nyl,nzl,nx,ny,nz]);
            data = s(ib:ie,jb:je,kb:ke,iscal);
            obj.appendSet(data,params);
          end

          % Close chunk file
          obj.close();
        end
      end
    end
end

function [ind] = locfun_proc_id(ii,jj,kk,nx,ny,nz)
  % local version of 'sub2ind_zero_row'
  ind=ii*ny*nz+jj*nz+kk;
end