🚀 go-pugleaf

Dear Kjetil,

About your question concerning DEMOS and Sim Plus Plus. I'm not very familiar
with Sim ++. There may be someone else listening who has used it. There is a
simulation package called Simple ++ written in C++. It is developed in Germany
and marketed in Scandinavia by COMSOL ab in Stockholm. This isn't the same one
that you mean ?

As far as DEMOS is concerned I use it everyday. DEMOS is a SIMULA class
consisting of about 2500 source code lines. It provides the process prototypes
and procedures which are very useful as building blocks when programming
discrete event simulation models. All you have to do is to learn what is there
to use and then prefix your own SIMULA program with the class identifier DEMOS.
This makes everything in DEMOS available within your own program. Using it is
the same as doing simulations through writting your own programs. The advantage
is total flexibility and very high execution speeds.

Using a package like Simple ++ is much more convenient. One does not have to do
any programming ( or only very little programming ). The model is built using
graphic symbols. The package generates program code automatically in the
background depending on which symbols are chosen and in which order
they are linked together. The graphics are pleasing to work with and one gets an
impression of immediate progress and accomplishment. The disadvantage is that
solutions that are outside of the facilities built into the package require
special solutions which the user must program himself. Another important
disadvantage is that these packages are most often written in languages which do
not implement coroutines. Simula is the only language that I know of that
implements coroutines and which at the same time has extremely effective
compilation and stability with a good debugger. Coroutines increase the speed of
discrete event simulations by a factor of 100 to 200 as compared to languages
like C++ , PASCAL or FORTRAN which do not.

Hope that this was of some help.

Henry Islo