[R]: add sd().
[R]: add sd().

flashxio/FlashX,icoming/FlashGraph,icoming/FlashX,icoming/FlashX,zheng-da/FlashX,icoming/FlashX,flashxio/FlashX,zheng-da/FlashX,icoming/FlashX,flashxio/FlashX,icoming/FlashGraph,icoming/FlashGraph,zheng-da/FlashX,icoming/FlashGraph,flashxio/FlashX,flashxio/FlashX,zheng-da/FlashX,zheng-da/FlashX,icoming/FlashX,icoming/FlashGraph,flashxio/FlashX