A few examples of problems with insert_elements.  It seems to be
in both Pelegant and elegant, and be present since at least several 
versions ago. 

1) Input file spear1.ele
   Trying to use load_parameters followed by insert_elements, 
   there is a problem when add_at_start=1
   As far as I can tell, it tries to copy the parameters of what was
   the first element onto the inserted element.  If the parameters are
   inconsistent, elegant stops with an error.  Changing the 
   inserted element to QUAD, for example, has no problem.
   Removing the load_parameters also fixes the issue, even though
   in this example load_parameters should not be changing anything.

2) Input file spear2.ele 
   This is almost the same thing as spear1.ele but the inserted element 
   is a QUAD and a MARK element has been placed at the start of the lattice 
   file.  This time there is an inconsistency because of FITPOINT copied
   from the MARK element.

3) Input file spear4.ele, compared to spear3.ele
   For these runs, there is no load_parameters and no add_at_start,
   just for simplicity.  When run with insert_before=0, insert_element
   seems to work fine.  With insert_before=1, it misses a few of the
   places where an element should be inserted.  It only seems to happen
   when the selected elements are very close to each other.

   

