FUNCTION dustem_compute_polsed,p_dim,stp,dustem_qsed,dustem_used,Q_sed,U_sed,_extra=extra,out_st=out_st

;+
; NAME:
;    dustem_compute_polsed
; PURPOSE:
;    Computes an SED from a given Dustem spectrum
; CATEGORY:
;    Dustem
; CALLING SEQUENCE:
;    sed=dustem_compute_polsed(p_dim[,st=][,_extra=][,/help])
; INPUTS:
;    p_dim      = parameter values
; OPTIONAL INPUT PARAMETERS:

;    stp        = Dustem structure

; OUTPUTS:

;    sed         : computed SED for filters in !dustem_data
;    dustem_qsed : SED in Q
;    dustem_used : SED in U

; OPTIONAL OUTPUT PARAMETERS:

;    stp        = Dustem output structure

; ACCEPTED KEY-WORDS:
;    help      = If set, print this help
; COMMON BLOCKS:
;    None
; SIDE EFFECTS:
;    None
; RESTRICTIONS:
;    The dustem idl wrapper must be installed
; PROCEDURE:
;    None
; EXAMPLES
;    
; MODIFICATION HISTORY:
;    Written by J.-Ph. Bernard
;    see evolution details on the dustem cvs maintained at CESR
;    Contact J.-Ph. Bernard (Jean-Philippe.Bernard@cesr.fr) in case of problems.

IF keyword_set(help) THEN BEGIN
  doc_library,'dustem_compute_polsed'
  dustem_polsed=0.
  goto,the_end
ENDIF

IF not keyword_set(stp) THEN BEGIN

  stp=dustem_run(p_dim)

  dustem_activate_plugins,p_dim/(*(*!dustem_fit).param_init_values),stp,res=res

ENDIF

If keyword_set(result) THEN result=stp
fact = 1.e4*1.E20/(4.*!pi)/(3.e8/1.e-6/(stp.polsed).wav)*1.e20/1.e7

StokesI = stp.sed.em_tot * fact   ;This is Total intensity I
largeP = stp.polsed.em_tot * fact   ;This is Polarized intensity P

Nwaves=(size(StokesI))[1]
polar_ippsi2iqu,StokesI,StokesQ,StokesU,largeP/StokesI,replicate(0.,Nwaves)

;stop

;MUST INCLUDE HERE ACTION OF PLUGIN WITH SCOPE MODIFY_POLAR_ANGLE
FOR i=0L,n_tags(*!dustem_scope)-1 DO BEGIN
  IF total(strsplit((*(*!dustem_scope).(i)),'+',/extract) EQ 'MODIFY_POLAR_ANGLE') THEN BEGIN
    angle=0.   ;A TROUVER !!!
    StokesQ=largeP*cos(2.*angle)
    StokesU=largeP*sin(2.*angle)
  ENDIF
ENDFOR

;ADDING PLUGIN TO SPECTRUM----------------

FOR i=0L,n_tags(*!dustem_scope)-1 DO BEGIN
  IF total(strsplit((*(*!dustem_scope).(i)),'+',/extract) EQ 'ADD_POLSED') THEN BEGIN
    StokesI+=(*(*!dustem_plugin).(i))[*,0]
    StokesQ+=(*(*!dustem_plugin).(i))[*,1]
    StokesU+=(*(*!dustem_plugin).(i))[*,2]
  ENDIF
ENDFOR

;-----------------------------------------

largeP=sqrt(StokesQ^2+StokesU^2)

dustem_qsed = (*!dustem_data.polsed).values * 0.
dustem_used = dustem_qsed

dustem_polsed = (*!dustem_data.polsed).values * 0.

goto,on_saute

Q_sed=StokesQ
U_sed=StokesU

if not isarray(StokesI) THEN stop 
;stop
;COMPUTE THE MODEL SED

;This will be the output of the fucntion

;MODIFYING VIA PLUGIN-------------- THIS BLOCK NEEDS TO BE UNDER THE DUSTEM_POLSED LINE 

FOR i=0L,n_tags(*!dustem_scope)-1 DO BEGIN

  IF total(strsplit((*(*!dustem_scope).(i)),'+',/extract) EQ 'MODIFY_POLSED') THEN BEGIN

    ;making sure it's the stokes plugin that gets used here

    iidx=where(tag_names(*!dustem_scope) eq 'SYNCHROTRON',countiidx)

    IF countiidx ne 0 THEN BEGIN 

      Q_dust=(*(*!dustem_plugin).(i))(0:n_elements((*(*!dustem_plugin).(i)))/4-1)
      U_dust=(*(*!dustem_plugin).(i))(n_elements((*(*!dustem_plugin).(i)))/4:n_elements((*(*!dustem_plugin).(i)))/2-1)
      Q_synch=(*(*!dustem_plugin).(i))(n_elements((*(*!dustem_plugin).(i)))/2:3*n_elements((*(*!dustem_plugin).(i)))/4-1)
      U_synch=(*(*!dustem_plugin).(i))(3*n_elements((*(*!dustem_plugin).(i)))/4:*)

    ENDIF ELSE BEGIN
      Q_dust=(*(*!dustem_plugin).(i))(0:n_elements((*(*!dustem_plugin).(i)))/2-1)
      U_dust=(*(*!dustem_plugin).(i))(n_elements((*(*!dustem_plugin).(i)))/2:*)
      Q_synch=Q_dust*0
      U_synch=U_dust*0
    ENDELSE

    ;THE ABOVE VARIABLES SHOULD BE ACCESSED DIRECTLY BY THE MPFIT_RUN.PRO
    Q_sed=Q_dust*fact+Q_synch
    U_sed=U_dust*fact+U_synch

    ;data the dustem_wrap will use
    dustem_qsed = dustem_polsed
    dustem_used = dustem_polsed

  ENDIF 
ENDFOR

on_saute:

;-------------------------------------------

  ;stop

IF !dustem_do_cc NE 0 AND !dustem_never_do_cc EQ 0 THEN BEGIN
  message,'DOING color correction calculations',/info
ENDIF ELSE BEGIN
  message,'SKIPPING color correction calculations',/info
ENDELSE

ind_polsed=where((*!dustem_data.polsed).filt_names NE 'SPECTRUM',count_polsed)

IF count_polsed NE 0 THEN BEGIN ; INCLUDE COLOR CORRECTIONS OF (Q,U) for dust & synch

  filter_names=((*!dustem_data.polsed).filt_names)(ind_polsed)

  spolsed=dustem_cc(stp.sed.wav,largeP,filter_names,cc=cc)
  dustem_polsed[ind_polsed]=spolsed

  ;PLUGIN 'STOKES' W/ scope='MODIFY' PART------------------------------------
  

  if isa(dustem_qsed) then begin 

    sqsed=dustem_cc(stp.sed.wav,StokesQ,filter_names,cc=cc)
    dustem_qsed(ind_polsed)=sqsed

  endif
  if isa(dustem_used) then begin

    sused=dustem_cc(stp.sed.wav,StokesU,filter_names,cc=cc)
    dustem_used(ind_polsed)=sused

  endif

  ;--------------------------------------------------------------------------
  

ENDIF

;For spectrum data points, interpolate in log-log
;Linear interpolation leads to wrong values, in particular where few
;wavelengths points exist in the model (long wavelengths).
ind_spec=where((*!dustem_data.polsed).filt_names EQ 'SPECTRUM',count_spec)
IF count_spec NE 0 THEN BEGIN

  dustem_polsed(ind_spec)=interpol(largeP,stp.wav,(((*!dustem_data.polsed).wav)(ind_spec)))

  ;STOKES PARAMS TREATMENT

  if isa(dustem_qsed) then dustem_qsed(ind_spec)=interpol(StokesQ,stp.wav,(((*!dustem_data.polsed).wav)(ind_spec)))  
  if isa(dustem_used) then dustem_used(ind_spec)=interpol(StokesU,stp.wav,(((*!dustem_data.polsed).wav)(ind_spec)))

ENDIF
out_st=stp

;clean pointers
heap_gc

the_end:

RETURN,dustem_polsed

END