anchor.diff:  c      read xyz input file
   c      -------------------
          call xyz_read_natoms(nat,fns)
  -       write(*,*) "nat",nat
  +       if(overb) write(*,*) "total number of atoms",nat
          allocate(c(3,nat))
          allocate(atag(nat))
          rewind(fns)
          call xyz_read(nat,c,atag,fns)
  -       write(*,*) "nat",nat
  +       angle = angle*pi/180.0
  +       v  = c(:,ida(1)) 
  +       v1 = c(:,ida(2))-v
  +       if(overb) write(*,*) "rotating by",angle
          do i=1,nid
  -         v  = c(:,ida(1)) 
  -         v1 = c(:,ida(2))-v
            x = c(:,id(i))
  -         write(*,*) "rotating by",angle
  -         angle = angle*pi/180.0
  -         write(*,*) "rotating by",angle
            call rot_around_axis(v(1),v(2),v(3),v1(1),v1(2),v1(3),
        >                        x(1),x(2),x(3),angle)
  -c         call
  -c     >   RotatePointAroundVector(x(1),x(2),x(3),
  -c     >                           v,v1,angle)
            c(:,id(i))=x
          end do
          call xyz_write(nat,c,atag,fno)
  -       angle = 62
  -       angle = angle*pi/180.0
  -       v(1) = -4
  -       v(2) = 0
  -       v(3) = -5
  -       v1(1) = 3
  -       v1(2) = 2
  -       v1(3) = -5
  -       x(1) = 4
  -       x(2) = 0
  -       x(3) = -5
  -         call rot_around_axis(v(1),v(2),v(3),v1(1),v1(2),v1(3),
  -     >                        x(1),x(2),x(3),angle)
  -         write(*,*) "x=",x(1),x(2),x(3)
  +       if(overb) write(*,*) "succesfull completion"
          stop
   c      if you reach this you are in trouble
  +1000   format(
  +     > "NAME:",/
  +     > " rotate rotate atoms ",
  +     > " around specified axis               ",//,
  +     >  "SYNOPSIS",/,
  +     > " rdf [-help] ",
  +     > " [-atoms ] [-axis ] [-angle ] ",
  +     > " input file(s) outpiut file ",//,
  +     >  "DESCRIPTION",/,
  +     > " This utility rotates selected atoms around the axis",
  +     > " from the xyz files",//,
  +     > " The required option are as follows:",/,
  +     > " -atoms   atom ids to be rotated",/,
  +     > " -axis   pair of atom ids used as the axis",/,
  +     > " -angle rotation angle",/,
  +     > " other options are as follows:",/,
  +     > " -help  prints out this message",/,
  +     > " -v  generate more verbose output"
  +     > )
   911    continue
          write(*,*) "Emergency STOP"
          write(*,*) message
  
positive.code:         double precision x1,y1,z1
          nrm = u*u+v*v+w*w
          nrm = sqrt(nrm)
          write(*,*) "nrm=",nrm
          u = u/nrm
          v = v/nrm
          w = w/nrm
  
negative.code: c          goto 911
  c       end if 
  30     continue
  c      -------------
  c      open io units
  c      -------------
  