function Xc = seqkeepcols (X,cols)

f=fields(X);
for i=1:length(f)
  if ~strcmp(f{i},'data')
    cmd = sprintf('Xc.%s = X.%s;',f{i},f{i});
    eval (cmd);
  end
end

for i=1:length(X.data)
  A = X.data{i};
  Xc.data{i} = A(:,cols);
end