fin = 'biotoy_ini_ecosim.nc'
fout = 'biotoy_ini_ecosim_32x32.nc'; % created with ncgen -b on a modifed cdl file

% get structure of nc file - use this to find list of variables
s = nc_info(fout);

% get dimensions of target
xi_rho = nc_getdiminfo(fout,'xi_rho');
eta_rho = nc_getdiminfo(fout,'eta_rho');

% step through all 3D variables that new copying to the new file
% 15,16 are temp,salt
% 22:84 are all the ecosim variables 

for i = [15 16 22:84]

  vname = char(s.DataSet(i).Name);
  disp(['doing ' vname])
  
  % get vertical vector
  datain = nc_varget(fin,vname,[0 0 0 0],[1 -1 1 1]);
  
  % copy it to all i,j index values
  dataout = repmat(datain,[1 1 eta_rho xi_rho]);
  
  % write to the new file
  nc_varput(fout,vname,dataout)
  
end