//执行下单-------------------------
平空:sellshort(开多平空条件 and holding<0, 手数,limitr,dxx+3*mindiff);//限价交易加3跳
平多:sell(开空平多条件 and holding>0,手数,limitr,knn-3*mindiff);//限价交易加3跳
开空:buyshort(开空平多条件 and holding=0,手数,limitr,knn-3*mindiff);//限价交易加3跳
开多:buy(开多平空条件 and holding=0, 手数,limitr,dxx+3*mindiff);//限价交易加3跳