Computer sciences for geophysicists. Part IX: the reliability of software, geophysical or otherwise
I expect some of you are still wondering what happened to the article in this series on graphics, devices, standards usage and so on. I still am. I suppose I ought to come clean and admit the real problem, which is not so much indolence on my part as the essentially ephemeral nature of graphics standards. It seems as though these standards possess a fifth force of nature to accompany weak, strong, electromagnetic and gravitational forces. This force is the political force. In essence, it works like this. Different graphics committees come together, exchange a DISON, an elementary particle of unbelievable mass which carries a Draft International Standard, no charm and little agreement. Having done this, the exchangers then diverge as rapidly as possible, often exceeding the speed at which free food and drinks disappear at Icebreakers. Thus it is with three-dimensional (3D) graphics (and FORTRAN 8X). After the various international organizations came together fleetingly like mayflies on a balmy day producing GKS, the Graphical Kemel System for two-dimensional (2D) graphics, they have now set off in opposite directions to produce Draft Standards for 3D which are almost but not quite, completely dissimilar. If you wish to keep up with things, the current protagonists are PHIGS (look it up) and GKS 3D. Coupled with other standards which seem to be vying for attention, such as CGI, (Computer Graphics Interface), which is a NQTS (Not Quite The Same) standard, I have temporarily given up and clutch at GKS 2D as a rock in an otherwise uneasy ocean. The very best thing you can do with graphics standards seems to be nothing as yet unless you are brave and rich enough to go it alone. The real subject I would like to address here is one which is rapidly assuming great importance to everybody involved in the use of software. This is the subject of reliability.