runmode:0;

input:length(20,5,60,5);
input:ratio(4,1,5,1);

variable:trend=0;
variable:stopprice=0;

prebarhigh:=ref(high,1);
prebarlow:=ref(low,1);

atr:=trimprice(ref(ema(high-low,length),1));
trailingstop:=ratio*atr;

if barpos>length and trend=0 then begin
 trend:=1;
 stopprice:=prebarlow-trailingstop;
 drawicon(1,prebarlow-trailingstop,8,0);
 drawtext(1,prebarlow-trailingstop,\'开多\',colorred,1); 
end

if trend=1 then begin
 if prebarlow-trailingstop>stopprice then
  stopprice:=prebarlow-trailingstop;
  
 if low<=stopprice then begin
  trend:=-1;
  stopprice:=prebarhigh+trailingstop;
  drawicon(1,prebarhigh+trailingstop,9,0);
  drawtext(1,prebarhigh+trailingstop,\'开空\',colorgreen,1);  
 end
 
 stickline(close>=open,high,close,1,1,colorred);
 stickline(close>=open,close,open,10,1,colorred);
 stickline(close>=open,open,low,1,1,colorred);
 stickline(close<open,high,open,1,0,colorred);
 stickline(close<open,open,close,10,0,colorred);
 stickline(close<open,close,low,1,0,colorred); 
end

if trend=-1 then begin
 if prebarhigh+trailingstop<stopprice then
  stopprice:=prebarhigh+trailingstop;
  
 if high>=stopprice then begin
  trend:=1;  
  stopprice:=prebarlow-trailingstop;
  drawicon(1,prebarlow-trailingstop,8,0);
  drawtext(1,prebarlow-trailingstop,\'开多\',colorred,1);  
 end
 
 stickline(close>=open,high,close,1,1,colorgreen);
 stickline(close>=open,close,open,10,1,colorgreen);
 stickline(close>=open,open,low,1,1,colorgreen);
 stickline(close<open,high,open,1,0,colorgreen);
 stickline(close<open,open,close,10,0,colorgreen);
 stickline(close<open,close,low,1,0,colorgreen);   
end

drawicon(trend=1,stopprice,10);
drawicon(trend=-1,stopprice,11);