SIMION 8.0 Issues/Bugs/Enhancements

Issue I223 [70,medium,resolved]
  Improvements in clipping line to rectangle.

  Clipping is used for things like detecting if a particle trajectory
    crosses a PA grid cell, splatting the particle if cell is an electrode.
  
  Problem known to affect versions prior to 8.0-beta12h:
    Particles may skip through PA at el=180deg due to numerical error in clipping.
    Problem seems to tend to occur when a particle is flying at
    an angle of elevation=180degrees.  Changing elevation to
    179.9999999... eliminates the effect.
    Problems occurs on some compilers and initally
      seemed related to the floating point code in matrix.cpp rt/el/az_matrix,
      but it it not so clear anymore since this may just be a side-effect.
    See theo/20060919 examples.
      Affects 7.0.1 and above and 8.0betas.  Also affects
      7.0.0 but to a somewhat lesser extent.

  Update 8.0-beta12h (2006-09-20): SIMION now treats nearly horizontal
    lines (i.e. 1/|slope| > 1e15) specially.  This issue is probably resolved now.
  
  Update: 8.0.6-TEST10 makes some further minor robustness improvements
    to 2D clip detection--e.g. treating X and Y exactly symmetrically.
  Update: 8.0.7.48/8.1.0.48 - made similar clip detection improvements
    in 3D.  See also Issue I588.