D. Bolier, A.Eliëns

contact the authors

dbolier@cs.vu.nl, eliens@cs.vu.nl

The code has been developed with AT&T 3.0.1 and GNU.

  A simulation is the execution in time of a model, represented by a 
  computer program, that gives information about the system being 
  investigated.
  The library sim adopts the method of the Discrete Event Simulation. 
  With this approach, the components of the model consist of events, 
  which are activated at certain points in time and in this way affect 
  the overall state of the system.  The points in time that an event is 
  activated are randomized, so no input from outside the system is 
  required. Events exist autonomously and they are discrete so between 
  the execution of two events nothing happens. The library sim provides 
  an event-based, as well as a process-oriented approach of writing a 
  simulation program.  With the process-oriented approach, the components
  of the program consist of entities, which combine several related 
  events into one entity.
  Sim is written in the C++ programming language. The library provides 
  classes, that can be used by writing a C++ simulation program.  
  We provided the library with such a functionality, that the resulting 
  language is similar to SIMULA.
  The library can be compiled to both a pure ASCII version as well as a
  HUSH version. If you run the library in HUSH mode, you can use the
  graphical features.
  

    doc : contains a postscript of the Users-Guide.
    examples : contains a variety of example programs.
    include : with the SIM header files.
    lib : contains SIM as an archive.
    man : with the manual pages.
    src : contains the SIM source files.
    tests : tests for the generator and probability distributions and for
            the event scheduling strategy.
  

    Makefile : to install SIM.
    README : the file you are currently reading.
    xinfo : to browse the manual pages.
    sim.tar : a tar of SIM, can be obtained anonymously.
  

    You should compile a simulation program (or make the library) with 
    a -DASCII definition when linking it to (or making) the ASCII version
    of the library. In the other case you should use the -DSIM and -DHUSH
    definitions.
  

    To install the SIM package you need to adjust the SIM and HUSH
    paths in the *.mk files of the directories : examples, src
    and the current one, to the paths you have choosen to install the 
    package. You might also check these files to see if the right compiler
    options are set (see above).
  

send them to the authors.

  The following things have been changed in version 2.0 :
  
    - You should always create and run a session.
    - If you link your programs to the Hush version you always get
      graphical output. As a consequence the simulation constuctor doesn't
      get tk as an argument anymore.
    - The histogram constructor gets a widget-path and the arguments as
      a string of options. The additional options are for the formatting
      of the output. The output for the (cumulative) frequency graph and
      table contains no statistis anymore. The statistics can be 
      generated by adding an extra histogram.
    - The methods suppress and scan of the simulation class don't exist 
      anymore. You can use the init method. Grafical output can be formatted.
    - The confidence method of the analysis class takes an options
      parameter now and the operator<< method has been removed.
      Invoking a method of this class will immediately result in output,
      which can be formatted.
    - The screen class behaves different. It is like the hush-canvas
      class except for the world-coordinates it uses. The widgets as the
      clock etc.. have been made independent.
    - The generator gets three seeds instead of one.
  

    - One program structure (sources and interface are clearer now).
    - The period for the generator is a factor of 7000 higher.
    - The graphical features are much more powerful. You can format almost
      anything you want (sizes, colors etc..). Furthermore the widgets 
      (histogram,results from analysis and simulation,screen,
       simulationclock,control,query) can be packed, be embedded in a 
       screen or made toplevel (instead of only be made toplevel).
  

Mail to the authors (dbolier@cs.vu.nl / eliens@cs.vu.nl)