/*--- 斑竹江湖令 及时单骑赶到 ---*/
data a;
input x y @@;
cards;
1 2 2 4 3 8 4 9 5 13
;
data  anno;
length  function $ 8;
retain  xsys '2' ysys '3' color 'black' when 'a';
do  i= 0 to 15 by .25;
  if (i+1)/int(i+1)=1 then
   do;
    tkht=2;
    text=left(put(i,2.));
   end;
  else
   do;
    tkht=1;
    text='';
   end;
  function='move';  y=i;  x=1.5;    output;
  function='draw';  y=i;  x=1.5-tkht/20; output;
  function='label'; y=i;  x=1.5;    output;
end;
run;

title1 "Move the Y axis to the middle of the graph";
axis1 origin=(15,15)pct   major=none   minor=none  length=60pct  
   order=(0 to 15 by 5) offset=(0,0) label=none  value=none color=white;
axis2 origin=(45,15)pct major=(h=-1) minor=(n=3 h=-.5) length=60pct
   order=(0 to 15 by 5) offset=(0,0);
axis3 origin=(15,15)pct   major=(h=-1)   minor=none  length=60 pct
   order=(-2 to 5 by 1)  offset=(0,0)  label=none ;
symbol1 i=j v=dot c=blue;
proc  gplot  data=a;
plot  y *x / vaxis=axis1 haxis=axis3 noframe href=1.5 vref=0 ;
plot2 y *x / vaxis=axis2 ;
run;
quit;

it is really a good but hard question!

求高手援助一把！实在着急啊，这个问题

在1.5处加一条垂直线不行吗？