On Tuesday 19 April 2005 17:10, John Lamb wrote:
Colin Carter wrote:
This is a good site John, I saw a good programme on the BBC about this. It disclosed a few secretes - I wish I had taped it. I couldn't see anything on this site about the 'bug', but I think that the BBC programme mentioned it. Any ideas?
I'm sure I saw the same programme but I don't recall the 'bug'. I guess a Google search might throw up something. There are also several books, which are bound to go into more detail. IIRC the programme was called Station X and is the sort of thing that gets repeated regularly on various history channels.
I believe object-oriented programming developed from an algol based language called Simula in the 1960s. Simula was designed for discrete event dimulation
GSS is not too bad for a quick solution.
I don't recall what GSS is. For fast discrete-event simulation I now usually use C++, though Java is also good. The only thing you need that isn't pure O-O is a priority queue. FORTRAN and similar languages are very poor because a priority queue has to be an arrray of fixed size and there aren't objects or pointers to functions to put in the queue; so you end up with an array of integers and code that looks at an integer and decided which function to call. OTOH FORTRAN is undeniably well suited to efficient matrix operations and the like.
-- JDL
GSS: General Simulation System or some such name. It is a while since I used it, but I lectured its use in time series simulation of processes. For example, a factory might be making X-Widgets. You add units (black box) which supply the basic units/raw materials required by our factory. One specifies the average number of units available per unit of time, and the distribution (eg Poisson) Add any number of supply units, add process units and queues and product shipment routes. And say GO. Each of the units takes inputs, crunches, with delays, and distributes outputs which are channelled to other units / queues until output occurs. Bottle-necks will show up as growing queues, and inadequate supplies will also show up, delays will show up- all in the output of summaries and statistics. Great fun. A kind of plug and play lego set. Regards, Colin