下面是笔者曾经收集的DDE源码，本人一直就用这个。公式源至网络。
DDX——
INPUT: P1(60,0,100),P2(5,0,100),P3(10,0,100);
REFLINE:0;
VAR0:=MIN(COUNT(ORDER(2),0),P1);
DDX:(BIGORDER(1) - BIGORDER(2)) * VOL/CAPITAL * 100,COLOR3D;
DDX1:EMA((BIGORDER(1) - BIGORDER(2)) * VOL/CAPITAL * 100,VAR0) * VAR0;
DDX2:MA(DDX1,P2);
DDX3:MA(DDX1,P3);
DRAWTEXTABS(0,0,'大单动向');
1,DOTLINE;

DDY——
INPUT: P1(60,0,100),P2(5,0,100),P3(10,0,100);
REFLINE:0;
VAR0:=MIN(COUNT(ORDER(2),0),P1);
VAR1:=EMA((2 - BIGORDER(1) - BIGORDER(2)) * VOL/(ORDER(1) + ORDER(2)),60);
DDY:(ORDER(2) - ORDER(1))/CAPITAL * VAR1 * 100,COLOR3D;
DDY1:EMA((ORDER(2) - ORDER(1))/CAPITAL * VAR1 * 100,VAR0) * VAR0;
DDY2:MA(DDY1,P2);
DDY3:MA(DDY1,P3);
DRAWTEXTABS(0,0,'涨跌动因');
1,DOTLINE;

DDZ——
REFLINE:0;
VAR0:=BIGORDER(1) * VOL/ORDER(1);
VAR1:=BIGORDER(2) * VOL/ORDER(2);
VAR2:=2 * VOL/(ORDER(1) + ORDER(2));
DDZ:(VAR0 - VAR1)/VAR2 * 100,COLORWHITE;
FLOATRGN((VAR0 - VAR1)/VAR2 * 100,VAR0 - VAR1,VAR0 > VAR1,RGB(255,0,0),VAR0 < VAR1,RGB(0,255,0));
DRAWTEXTABS(0,0,'大单差分');

下面这个好像在理想搜到的。（大智慧－L2 DDE源码）
ddy
input:p1(60),p2(5),p3(10);
DDy:(ORDER(2)-ORDER(1))/CAPITAL*100,COLORSTICK,linethick2;
DDy1:ema(DDy,p1)*p1;
DDy2:MA(DDy1,p2);
DDy3:MA(DDy1,p3);
0.1,DOTLINE,colorblue;
DRAWTEXTABS(0,0,'涨跌动因');

ddx
input:p1(60),p2(5),p3(10);
refline:0;
DDX:(BIGORDER(1)-BIGORDER(2))*VOL/CAPITAL*100,COLORSTICK,linethick2;
DDX1:ema(DDX,p1)*60.177;
DDX2:MA(DDX1,p2);
DDX3:MA(DDX1,p3);
DRAWTEXTABS(0,0,'大单动向');

ddz
DDZ:=(ORDER(2)-ORDER(1))/(ORDER(2)+ORDER(1))*200;
DDZ1:=(ORDER(2)-ORDER(1))/(ORDER(2)+ORDER(1))*170;
FILLRGN(DDZ,DDZ1,DDZ>DDZ1,RGB(255,0,0),DDZ<DDZ1,RGB(0,255,0));
DRAWTEXTABS(0,0,'大单分差');

还有分时的DDE
DDX
input:p1(60),p2(5),p3(10);
variable:ddx=0;
DDX:(ordervol(1,2)-ordervol(2,2))/capital*100,colorstICK,LINETHICK2;
DDX累积:SUM(ddx,0);
drawtextabs(0,0,'大单动向');