c********************************************************************
	
	SUBROUTINE t_vrf(v,dv,r,dr,fesh,dfesh,teff,dteff)
	
c routine PUBLIC du module mod_photo

c calcul de la Teff en utilisant les Mv, Mr et [Fe/H]
c suivant Alonso et al. A&A 313, 873, 1996 (formules 4 et 5),

c Auteur: P. Morel, Laboratoire Lagrange, O.C.A., CESAM2k

c entrees
c	v, dv, r, dr : magnitudes absolues V et R et precision
c	fesh, dfesh : [Fe/H] et precision

c sorties
c	teff, dteff : Teff et precision

c------------------------------------------------------------------------

	USE mod_kind
	
	IMPLICIT NONE
	
	REAL (kind=dp), INTENT(in) :: v, dv, r, dr, fesh, dfesh
	REAL (kind=dp), INTENT(out) :: teff, dteff
	
	REAL (kind=dp) :: vmr, teta, dteta_vmr, dteta_fesh
	
	LOGICAL :: cas1, cas2, init=.TRUE.
 	
c-----------------------------------------------------------------------

	IF(init)THEN	!initialisations
	 init=.FALSE. 
	 WRITE(*,10)
10	 FORMAT('calcul de la Teff en utilisant les Mv, Mr et [Fe/H]',/,
	1 'suivant Alonso et al. A&A 313, 873, 1996 (formules 4 et 5)',/)
	ENDIF

	vmr=v-r	

	cas1=(0.25d0 <= vmr .AND. vmr <= 0.6d0) .AND.
	1 (0.5d0  >= fesh .AND. fesh > -0.5d0)
	cas1=cas1 .OR. (0.3d0  <= vmr .AND. vmr <= 0.6d0) .AND.
	1 (-0.5d0 >= fesh .AND. fesh > -1.5d0)
	cas1=cas1 .OR. (0.4d0  <= vmr .AND. vmr <= 0.6d0) .AND.
	1 (-1.5d0 >= fesh .AND. fesh > -3.5d0)

	cas2=(0.6d0 <= vmr .AND. vmr <= 1.4 d0) .AND.
	1 (0.5d0  >= fesh .AND. fesh > -0.5d0)
	cas2=cas2 .OR. (0.6d0 <= vmr .AND. vmr <= 0.75d0) .AND.
	1 (-0.5d0 >= fesh .AND. fesh > -2.5d0)
	cas2=cas2 .OR. (0.6d0 <= vmr .AND. vmr <= 0.7d0 ) .AND.
	1 (-2.5d0 >= fesh .AND. fesh > -3.5d0) 
	
	IF(cas1)THEN		!formule 4
	 teta=0.474d0+vmr*(0.755d0+0.005d0*vmr-0.003d0*fesh)	!formule 4
	1 -fesh*(0.027d0+0.007d0*fesh)
	 dteta_vmr=0.755d0+0.010d0*vmr-0.003d0*fesh
	 dteta_fesh=-0.027d0-0.014d0*fesh-0.003d0*vmr
	ELSEIF(cas2)THEN	!formule 5
	 teta=0.524d0+vmr*(0.724d0-0.082d0*vmr-0.166d0*fesh)	!formule 5
	1 +fesh*(0.074d0-0.009d0*fesh)
	 dteta_vmr=0.724d0-0.164d0*vmr-0.166d0*fesh
	 dteta_fesh=0.074d0-0.018d0*fesh-0.166d0*vmr	
	ELSEIF(vmr <= 0.6)THEN
	 WRITE(*,3)vmr,fesh
3	 FORMAT(' V-R=',f8.4,' et [Fe/H]=',f8.4,' hors des limites',/,
	1 'pour Teff on utilise quAND meme la formule 4')
	 teta=0.474d0+vmr*(0.755d0+0.005d0*vmr-0.003d0*fesh)	!formule 4
	1 -fesh*(0.027d0+0.007d0*fesh)
	 dteta_vmr=0.755d0+0.010d0*vmr-0.003d0*fesh
	 dteta_fesh=-0.027d0-0.014d0*fesh-0.003d0*vmr
	ELSE
	 WRITE(*,4)vmr,fesh
4	 FORMAT(1x,' V-R=',f8.4,' et [Fe/H]=',f8.4,' hors des limites',/,
	1 'pour Teff on utilise quAND meme la formule 5')
	 teta=0.524d0+vmr*(0.724d0-0.082d0*vmr-0.166d0*fesh)	!formule 5
	1 +fesh*(0.074d0-0.009d0*fesh)
	 dteta_vmr=0.724d0-0.164d0*vmr-0.166d0*fesh
	 dteta_fesh=0.074d0-0.018d0*fesh-0.166d0*vmr
	ENDIF
	teff=5040.d0/teta
	dteff=teff/teta*(dteta_vmr*(dv+dr)+dteta_fesh*dfesh)
	dteff=ABS(teff)

	RETURN
		
	END SUBROUTINE t_vrf