通达信波段低点（源码 副图/选股 贴图）

A1:=DRAWLINE(HIGH =HHV(HIGH,13)
,HIGH,LOW =LLV(LOW,13),LOW,0);
B1:=DRAWLINE(LOW =LLV(LOW,13)
,LOW,HIGH =HHV(HIGH,13),HIGH,0);
C1:=LOW =LLV(LOW,13);
ZD:A1=B1