function V4XS2SC,in,verbose=v,index=ix,outdex=ox,ocoords=ocoords

;;;
;;; Check out input keywords for existence...
;;;
if (isvalid(ix) or isvalid(ox)) then $
    if(total(where( (ix ne [0,1,2,3]) or (ox ne [0,1,2,3]) )) ge 0) then $
        print,"WARNING - V4XS2SC - ignoring indexing!"
v = keyword_set(v)

ix = [0,1,2,3]
ox = ix
iu = ix+5
ou = ox+5

;;;
;;; Calculate the Earth-Sun distance...
r = sunearthdist(in.(ix(0)),in.(iu(3)))
if(v) then print,"V4XCS2SC: earth-sun distance is ",r,in.(iu(3))

;;;
;;; Place the plane of the sky at the Sun if radius is undefined.
i2 = in
if(not (i2.defined)(3)) then i2.(3) = r

;;;
;;; Convert from Earth spherical to Earth-centered Cartesian...
i2 = v4xsph2cart(i2,v=v,index=[0,1,2,3],outdex=[0,3,1,2],ocoord="blecch")

if not data_chk(i2,/struct) then return,0

;;;
;;; Translate the origin from the Earth to the Sun...
i2.(ix(3)) = r - i2.(ix(3))

i2.coords="Solar Cartesian"

i2 = v4canon(i2)
return,i2
end