PRO CENTROIDW,ARRAY,XCEN,YCEN
;
;
ON_ERROR,2              ;Return to caller if an error occurs
S=SIZE(ARRAY)
if S(0) ne 2 then message, 'Array is not 2-dimensional.'

totarr = total(ARRAY)       ; Get the total value
YCEN   = total(ARRAY#findgen(n_elements(ARRAY(0,*)))) / totarr  
XCEN   = total(findgen(n_elements(ARRAY(*,0)))#ARRAY) / totarr  

return 
end