A click on the Causes Strip graph will quickly tell you why. Select Population into the Workbench and click on the Graph tool:Įven though you entered a higher initial value for births, the base simulation population is quickly catching up. You can enter a new value for births, or a new Continue until time. NOTE It is not possible to back up a game for a model that includes any of the pure delays (DELAY FIXED, INFORMATION, MATERIAL, BATCH or CONVEYOR) or QUEUE functions.Īt this point the Game Control dialog should show Time=50 at the top. The change in rabbit population from month t to month t + 1 is p t + 1 p t, which you set equal to 20 of the population p t at the beginning of the month: (1) p t + 1 p t 0.2 p t. You let the variable p t be the number of rabbits in month t. If you click on this you will be asked the time you want to back up to. Based on this information, you postulate the following model for rabbit population growth. This is a good way to replicate the results of a gaming session from a small file or for a slightly different model.īackup can be used to back up the game to a prior time. The decisions will be read and the game advanced to the recorded termination time. These files can be created by hand or using the Model>Export Gaming menu item. Load Decisions… is used to read in a gaming input file with decisions stored by time. The simulation will progress until time 50 (you can also cancel by pressing the Cancel button during the simulation).
#Rabbit population simulation game update#
Click on births, click on Modify and enter a new value for births.Ĭlick on the Update button and 6 will go up into the list of gaming parameters.Ĭontinue until determines how long Vensim will run the model before coming back to you to ask for input. This dialog functions much the same way the Constant Change dialog functions except the value editing box remains visible below the list. Open the Simulation Control dialog and click on Game. If you just run this model it will show exponential growth in Population. Population=INTEG(births-deaths,100)~Rabbit~|īirths=GAME(Population*.03)~Rabbit/Month~| A computer simulation was used to portray foxes feeding on rabbits. For example, suppose you had a simple population model such as The system in question consisted of a predator-and-prey ecology. You can do this by selecting the subtype Gaming under the type Auxiliary in the Equation Editor. To run a simulation interactively as a game, you need to define one or more variables as GAME variables. The Toolbar technique works better so this approach is really only useful when sketch information is missing or incomplete. You can also run gaming simulations from the Simulation Control Dialog.
#Rabbit population simulation game how to#
We discussed how to run a gaming simulation from the Toolbar above.
0 kommentar(er)
