User Tools

Site Tools


concepts:scenario_management_-_understanding_scenarios_variables_and_instances

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
concepts:scenario_management_-_understanding_scenarios_variables_and_instances [2009/10/16 15:19]
deryn.crockett
concepts:scenario_management_-_understanding_scenarios_variables_and_instances [2009/11/05 20:13] (current)
deryn.crockett
Line 1: Line 1:
 ===== Scenario Management ===== ===== Scenario Management =====
  
-During a simulation run, calculators in a model are run with given values for control variables to produce a set of outputs.+During a simulation run, calculators in a model are run with given values for control variables to produce a set of outputs.  Control variable values are saved as instances. ​ A collection of a instances for all variables in the model is saved as a scenario. ​ A scenario may be described as an instantiation snapshot. ​ By using scenarios, a user can quickly recall a set of variable values used to create a given model output and can compare sets of values between different scenarios. ​ There is a one-to-one relationship between an input set of variable values and the corresponding model output so that the output may always be derived from the input. ​ The relationship among variables, instances, and scenarios is shown in the diagram below.
  
 {{concepts:​ScenarioManagement.jpg}} {{concepts:​ScenarioManagement.jpg}}
 +
 +Key points to note:
  
   * An instance is a value for a variable.   * An instance is a value for a variable.
   * All variables must have at least one instance.   * All variables must have at least one instance.
   * Variables can have multiple instances.   * Variables can have multiple instances.
-  * For a simulation run, variables use one and only one instance +  * For a simulation run, variables use one and only one instance. 
-  * Saved collection of instances is a scenario +  * Saved collection of instances is a scenario. 
-  * Instances do not have to be used in any scenario+  * Instances do not have to be used in any scenario
 +  * Worksheet reflects the current set of instances being used. 
 + 
 + 
  
-Worksheet reflects the current set of instances being used 
concepts/scenario_management_-_understanding_scenarios_variables_and_instances.1255706349.txt.gz · Last modified: 2009/10/16 15:19 by deryn.crockett