clear
window 0
defaults
ps = 14
inquire 'Enter plotsymbol code ('//rchar(ps)//')' ps
!
define\constants
generate x 0,,2*pi,25
y=sin(x)+2*ran(x)
generate\random ey1 0 .5 25
generate\random ey2 0 .5 25
set
  %plotsymbolsize 2
  plotsymbol -ps
  plotsymbolcolor blue

graph x y ey1,,ey2
!
get
 %xloweraxis xlx
 %xupperaxis xux
 %yupperaxis yux
 
set
 %textheight 6
 textfont 'ArialBlack'
 %xtextlocation (xlx+xux)/2
 %ytextlocation yux+2
 textalign 2
 textinteractive 0
 
text 'Asymmetric error bars'