DESCR("computation cost factors", "[%s]", comp_cost.to_string().c_str());
DESCR("communication cost factors", "[%s]", comm_cost.to_string().c_str());
DESCR("minimum data transfer amount", "%g", min_transfer_amount);
DESCR("computation cost factors", "[%s]", comp_cost.to_string().c_str());
DESCR("communication cost factors", "[%s]", comm_cost.to_string().c_str());
DESCR("minimum data transfer amount", "%g", min_transfer_amount);