構造格子の格子点で定義された倍精度実数の属性を読み込む。
call cg_iric_read_grid_real_node(fid, label, values, ier)
ier = cg_iRIC_Read_Grid_Real_Node(fid, label, values);
values = cg_iRIC_Read_Grid_Real_Node(fid, label)