;+
; 
;             NAME : sp_setup_dots
; 
;          PURPOSE : To make filled circles the user defined symbol.
;
; CALLING SEQUENCE : sp_setup_dots
; 
;           INPUTS : None.
; 
;  OPTIONAL INPUTS : None.
; 
;         KEYWORDS : size - the size of the dots default for ps is
;                    0.3, for xterm 0.6.
; 
;          OUTPUTS : None.
;
; OPTIONAL OUTPUTS : None.
;
;    COMMON BLOCKS : None.
; 
;          EXAMPLE : IDL> sp_setup_dots,size=2 ;; BIG dots
;                    IDL> plot,x,y,psym=8
;
;    SPECIAL CALLS : None.
;
;          WRITTEN : HPW Many moons ago.
; 
;-

pro sp_setup_dots,size=size,nofill=nofill

if keyword_set(nofill) then fill = 0 else fill = 1

if !d.name eq 'PS' then r_default = 0.3 else r_default = 0.6

if keyword_set(size) then r = size else r = r_default

a = findgen(16)*(!pi*2.0/16)
usersym,r*cos(a),r*sin(a),fill=fill

return
end