Display of field quantities in a 3D electromagnetics program

Summary form only given. A general program, known as MEGA, has been developed for solving 2D and 3D electromagnetic problems. The discussion mainly concerns the pre- and post-processor sections of MEGA. The 3D meshes are derived from 2D meshes by `extruding´ along one coordinate. Advantages of this approach include easy data handling in the program, also a user can visualise where he is in the model and move around very easily. A major disadvantage is that some devices, at worst, cannot be meshed in this way and, at best, can be modelled only by including much redundant detail in the problem. In the post processing state it is important that a user can easily view any of the quantities which are important to the design of a device. This is done by `slicing´ up the device in an arbitrary way and displaying the required quantities on the surface of the `cuts´. Holography opens up the possibility of viewing computer created models almost in 3D. Some of these techniques are described