C DVBOUL    SOURCE    JK148537  24/10/30    21:15:04     12058          
      SUBROUTINE DVBOUL(s,centre,ray,nbrobl,nombre,ib,igau)
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8 (A-H,O-Z)
c     ***********************************************************
c     calcul de la plus petite hypersphere, dimension espace < 6
c     algorithme inspiré de miniball 
c     ***********************************************************
      integer lisr(nbrobl)
      real*8 centre(nbrobl-1),rayon(nbrobl-1)
      real*8 s(nbrobl-1,nombre)
          
      klisp = 0
 10   continue
      lisr(1) = 1
*      write(6,*)'advblis1',(lisr(ju),ju = 1,nbrobl)
      do iu = 1,nbrobl-1
        centre(iu) = s(iu,1)
      enddo
      ray2 = 0.D0
      call dvdmax(s,centre,ray2,lisr,nbrobl,nombre,indx)
*      write(6,*)'dvboul1',klisp,((centre(ju)/1.e6),ju=1,nbrobl-1),indx
      if(indx.gt.0) then
        lisr(2) = lisr(1)
        lisr(1) = indx
        do iu = 1,nbrobl-1
          centre(iu) = (s(iu,lisr(1)) + s(iu,lisr(2)))*0.5D0
          rayon(iu) = s(iu,lisr(1)) - centre(iu)
        enddo
        ray2 = rayon(1)*rayon(1) + rayon(2)*rayon(2) + 
     &2.D0*rayon(3)*rayon(3)
        if (nbrobl.gt.4) then
         ray2 = ray2 + 2.D0*(rayon(4)*rayon(4) + rayon(5)*rayon(5))
        endif
          ray = dsqrt(ray2)
      else
*       write(6,*) 'boulA',klisp
       return
      endif
      klisp = klisp + 1
*     verification 
*      write(6,*)'advblis2',(lisr(ju),ju = 1,nbrobl)
          call dvdmax(s,centre,ray2,lisr,nbrobl,nombre,indx)
*      write(6,*)'dvboul2',klisp,((centre(ju)/1.e6),ju=1,nbrobl-1),indx
* nouvel essai 2D
      if(indx.gt.0) then
        lisr(2) = lisr(1)
        lisr(1) = indx
        do iu = 1,nbrobl-1
          centre(iu) = (s(iu,lisr(1)) + s(iu,lisr(2)))*0.5D0
          rayon(iu) = s(iu,lisr(1)) - centre(iu)
        enddo
        ray2 = rayon(1)*rayon(1) + rayon(2)*rayon(2) 
     &+2.D0*rayon(3)*rayon(3)
        if (nbrobl.gt.4) then
         ray2 = ray2 + 2.D0*(rayon(4)*rayon(4) + rayon(5)*rayon(5))
        endif
          ray = dsqrt(ray2)
         klisp = 2
      else
*       write(6,*) 'boulB',klisp
       return
      endif
      klis0 = 0
      NDIM = 2
      ray2max = ray2

 20   continue 
*     verification 
          call dvdmax(s,centre,ray2,lisr,nbrobl,nombre,indx)
                    
          if (ray2max.gt.0) then
            delray = dabs((ray2 - ray2max)/ray2max)
          else 
            delray = 0.d0
          endif
          if(ib.eq.230.and.igau.eq.6.and..false.) then
      write(6,*) 'oul',klisp,klis0,ndim,indx,ray2,delray
      write(6,*) ((centre(ju)/1.e6),ju=1,nbrobl-1)
          endif
          ray = dsqrt(ray2)
          if(indx.eq.0.or.delray.lt.1.D-10) then
*       write(6,*) 'boulklisp',klisp,ndim
            return
          else
            if (ray2.gt.ray2max) ray2max = ray2
            do ll = ndim,2,-1
              lisr(ll) = lisr(ll-1)
            enddo
            lisr(1) = indx
            klisp = klisp + 1
          if(klisp.gt.nombre) then
           call erreur(21)
*           write(6,*) 'pb ', ib,igau
           return
          endif
            if(klisp-1.eq.klis0+ndim) then
              ndim = ndim + 1
              if (ndim.eq.nbrobl+1) then
c        interr(1) = ib
c        interr(2) = igau
       write(6,*) 'arret boules',klisp, ib,igau,klis0,ndim
         call erreur(5)
*        call erreur(-366)
              return
              endif
              klis0 = klisp - 1
              nd = ndim
            else  
            endif
              call dvhyp2(nbrobl,nombre,s,nd,lisr,iok,r2,centre)
              ray2 = r2
              goto 20
          endif

      RETURN
      END