{

  int ntimestep = update->ntimestep;

  // perform dump at start of run if last dump was not on this timestep

  // perform dump at start of run if current timestep is multiple of every

  //   and last dump was not on this timestep

  // set next_dump to multiple of every

  // will not write on last step of run unless multiple of every

  // set next_dump_any to smallest next_dump

  if (ndump) {

    for (int idump = 0; idump < ndump; idump++) {

      if (last_dump[idump] != ntimestep) {

      if (ntimestep % dump_every[idump] == 0 && 

	  last_dump[idump] != ntimestep) {

	dump[idump]->write();

	last_dump[idump] = ntimestep;

      }