QueGauss

The Discrete Simulation module for GAUSS

QueGauss allows you to simulate discrete systems involving queues. These include such things as hospital patient services, manufacturing processes and phone exchanges. Using QueGauss you can examine the statistics of waiting times, transit times and utilization of resources.

QueGauss consists of items, event procedures and queues.
Items are the things that flow through the model. You can define any number of item types each with their own attributes (both numeric and character).
Event procedures are GAUSS procedures that process the items.
Queues are available to store items that are waiting to be processed. Special print procedures allow you to display the contents of items and queues using user defined formats.

Features

Basic Statistics are automatically collected for all items and queues.
Accumulators can be defined to collect other statistics (see plot top right).
Plots of the variations in statistics as well as frequency tables can also be accumulated.
A wide range of built-in distributions are provided:- exponential (Poisson), Erlang, Hyper-exponential, Normal, Uniform and Integral Uniform.
All of GAUSS' programming and plotting functions are available.
Random samples of any distribution (discrete or continuous) can be obtained given its cumulative distribution.
Extensive error checking built-in which can be disabled for faster runs.
Intelligent printing functions to display items and queues.
Verbose mode which allows you to trace backwards and forwards through the simulation's execution.
Transit and Markitem procedures to determine the transit time of items.
Number of items in existence at one time limited only by memory.
Memory compaction allows unlimited number of items during the course of the simulation.
The start up phase of a simulation can be easily ignored.
80 page instruction manual including tutorial, detailed examples, guidelines for writing a simulation, debugging tips, command reference and index.

STATISTICAL FUNCTIONS

DEFACCUM        Set up an accumulator
ACCUM           Accumulate statistics
FORCEACC        Force accumulator to output to plot matrix, if one defined
CLRSTAT         Clear the statistics for a queue, item type or accumulator
ACCSTAT         Return the statistics for an accumulator
ITEMSTAT        Return the statistics for an item type
QUESTAT         Return the statistics for a queue

QUEUING FUNCTIONS

QUEGAUSS        Main QueGauss Procedure.
Processes       Event Queue
QUESET          Reset default values and clear statistics
STOPQUE         Set stop flag to halt simulation
QUEEVENT        Add event to event queue
DEQEVENT        Remove event from event queue
DEFQUE          Set up a queue
QUE             Add item to queue
QUELEN          Return the current length of the queue
GETQUE          Get all the items in a queue
GETQUE2         Get all the items in a queue together with the time queued
DEQUE           Remove item from queue
DEQUE2          Remove item from queue together with time it was queued
CRTITEM         Create an item
DSTITEM         Destroy an item
PUTITEM         Store values of array of items

STATISTICAL DISTRIBUTIONS

CONTDIST        Random sample of a continuous distribution
CONTTAB         Return a point from a continuous table
DISCDIST        Random sample of a discrete distribution
DISCTAB         Return a point from a discrete table
ERLDIST         Random sample of the Erlang distribution
EXPDIST         Random sample of the Exponential distribution
HYPDIST         Random sample of the Hyper-exponential distribution
INTDIST         Random integer of Uniform distribution
NORMDIST        Random sample of the Normal distribution
UNIFDIST        Random sample of the Uniform distribution

PRINTING FUNCTIONS

PRTEVENT        Print event queue
PRTITEM         Print item
PRTITEMS        Print all items
PRTQUE          Print queue
PRTTYPE         Print type of item and index number
PRTSTAT         Print the statistics for a queue, item type or accumulator

MISCELLANEOUS FUNCTIONS

CHKTYPE         Check type of item against given type
ITEMTYPE        Return type of item
MARKITEM        Mark item with the current time
TRANSIT         Return time since last mark of item
STEPS           Reform x,y data into a series of steps for plotting

GLOBAL CONTROL VARIABLES

_m              constant, missing value.
quetime         the current simulation time.
_quedeb         1 for debugging checking (default 1)
_queverb        1 for verbose QueGauss (default 0)
_queprt         print message every _queprt destroys (default 100)
_quepack        pack after this many destroys (default 500).
                Set _quepack to 0 to disable packing.
_qgkey          1 to check keyboard for user interrupt key, H (default 1).
                Set to 0 to inhibit keyboard check and suppress the _queprt message.
                When checking for the user interrupt key, all other key strokes are consumed.

Stefan Steinhaus, webmaster@steinhaus-net.de