C DVHYP2    SOURCE    KICH      19/10/25    21:15:08     10351          
      subroutine dvhyp2(nbrobl,nombre,s,n,liste,iok2,r2,centre)
c
c     *************************************************
c     trouver la plus petite hypersphere circonscrite
c     aux points de la liste
c     *************************************************
c
      implicit real*8 (a-h,o-z)
      implicit integer (i-n)
      real*8 s(nbrobl-1,nombre)
      integer liste(6)
      real*8 tns(5,5),vc(5),res(5),u(5),v(5),centre(5)

      iok2 = 0
      do mm=1,5
       u(mm) = 0.d0
       v(mm) = 0.d0
       vc(mm) = 0.d0
      enddo
      n    = n-1
      do k=1,n
         do l=k,n
            do ict=1,nbrobl-1
              u(ict) = s(ict,liste(l+1))-s(ict,liste(1))
              v(ict) = s(ict,liste(k+1))-s(ict,liste(1))
            enddo
            tns(k,l) = u(1)*v(1) + u(2)*v(2) + 2.d0*(u(3)*v(3)
     & + u(4)*v(4) + u(5)*v(5))
            tns(l,k)=tns(k,l)
         enddo
         do ict=1,nbrobl-1
            u(ict) = s(ict,liste(k+1))-s(ict,liste(1))
         enddo
         vc(k) = (u(1)**2+u(2)**2+2.*(u(3)**2+u(4)**2+u(5)**2))/2.d0
      enddo
      call dvinve(n,tns,vc,res,iok3)
      if(iok3.eq.1) go to 525
      iok2 = 0
      go to 600
 525  continue
      do k=1,nbrobl-1
        centre(k)=s(k,liste(1))
        do l=1,n
          centre(k)=centre(k)+res(l)*(s(k,liste(l+1))-s(k,liste(1)))
        enddo
        vc(k)=s(k,liste(1))-centre(k)
      enddo
      r2 = (vc(1)**2+vc(2)**2+2.*(vc(3)**2+vc(4)**2+vc(5)**2))
 600  continue
      return
      end