;+
;PROCEDURE: mult_data, n1,n2
;PURPOSE:
;   Creates a tplot variable that is the product of two other tplot variables.
;INPUT: n1,n2  tplot variable names (strings)
;-
PRO mult_data,n1,n2,newname=newname
get_data,n1,data=d1
get_data,n2,data=d2
if not keyword_set(d1) or not keyword_set(d2) then begin
   message,/info,'data not defined!'
   return
endif
if not keyword_set(newname) then newname = n1+'^'+n2
y2 = interp(d2.y,d2.x,d1.x)
ratio = d1.y
case ndimen(d1.y) of
 1: ratio = ratio*y2
 2: ratio = ratio*(y2 # replicate(1.,dimen2(d1.y)))
 endcase 
dat = {x:d1.x,y:ratio}
store_data,newname,data=dat
return
end