C LNUD3D    SOURCE    PV090527  23/01/27    21:15:48     11574          
      subroutine LNUD3D(long,xe3d,NBNMAX3D,NBNB3D,dir3)

c     calcul taille de l element a partir des coordonnees des noeuds
c     tables de dimension fixe pour resolution des sytemes lineaires 
c     Sellier 26/04/2021
      implicit real*8 (a-h,o-z)
      implicit integer (i-n)

c     declaration 
      real*8 dir3(3),long    
      integer i,j
      real*8 dmin,dmax,dim1
      integer NBNMAX3D,NBNB3D
      real*8 xe3d(3,NBNMAX3D)

         dmin=0.d0
         dmax=0.d0
         do i=1,nbnb3d
          if (i.eq.1) then
c           initialisation dmin dmax sur 1er neoud          
            dim1=0.d0
            do j=1,3
                dim1=dim1+xe3d(j,i)*dir3(j)
            end do
            dmin=dim1
            dmax=dim1
          else
            dim1=0.d0
            do j=1,3
                dim1=dim1+xe3d(j,i)*dir3(j)
            end do
            if (dim1.lt.dmin) then
               dmin=dim1
            else if (dim1.gt.dmax) then
               dmax=dim1 
            end if
          end if    
         end do          
         long=dmax-dmin
         if(long.eq.0.) then
             print*,'dir3',dir3,'long',long
             err1=1
             return
         end if
        return
        end