FUNCTION pf2eps, data0, $
                 LOGARITHMIC=logarithmic, $
                 REVERSE=reverse, $
                 TO_LOG=to_log, $
                 FROM_LOG=from_log, $
                 SILICON=silicon, $
                 SOLABUFILE=solabufile

@compile_opt

@solabu_var
IF N_ELEMENTS(solabufile) EQ 0 THEN solabufile=''
solabu, FILE=solabufile

;make local copy
IF N_ELEMENTS(data0) NE 0 THEN data=data0

ndata=N_ELEMENTS(data)

IF N_ELEMENTS(silicon) EQ 0 THEN silicon=0
IF N_ELEMENTS(logarithmic) EQ 0 THEN logarithmic=0
IF N_ELEMENTS(to_log) EQ 0 THEN to_log=logarithmic
IF N_ELEMENTS(from_log) EQ 0 THEN from_log=logarithmic

ion=1
offset=12
IF silicon THEN BEGIN 
   ion=14
   offset=6
ENDIF

PRINT,' [PF2EPS] WARNING: the following piece of code has not been debugged.'
i=(WHERE(data.z EQ ion))[0]
IF i NE -1 THEN BEGIN
; should use H or Si from data
   xX=data[i].abu
   IF (NOT logarithmic) AND (not from_log) THEN $
      xX=ALOG10(xX)
ENDIF ELSE BEGIN
; use solar value if not present
   xX=alog10(sol_el_mol[sol_z2el[ion]])
ENDELSE
shift=-offset+xX-ALOG10(sol_el_mol[sol_z2el[data.z]])

IF N_ELEMENTS(reverse) EQ 0 THEN reverse=0
IF reverse EQ 1 THEN shift*=-1

; in the following the first case can do both, however, the second
; case does not require conversion if linear
; (I could have written it the other way as well, of course, but the
; logarithmic case seems to be the more common one)
IF to_log NE from_log THEN BEGIN
    IF from_log NE 0 THEN data=logy2y(data,/rev)
    data.abu-=shift
    IF to_log NE 0 THEN data=logy2y(data)
ENDIF ELSE BEGIN
    IF logarithmic EQ 0 THEN BEGIN
        data.abu/=10.D0^shift
        data.sigma/=10.D0^shift
    ENDIF ELSE BEGIN
        data.abu-=shift
    ENDELSE
ENDELSE

RETURN, data

END