Differences

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

--- concepts:scenario_management_-_understanding_scenarios_variables_and_instances [2009/10/16 15:05]
deryn.crockett
+++ concepts:scenario_management_-_understanding_scenarios_variables_and_instances [2009/11/05 20:10]
deryn.crockett
@@ Line 1: / Line 1: @@
 ===== Scenario Management =====
-set of values for all control variables in model
+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.  Collections of instances are saved as scenarios.  A scenario is also known 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 within different scenarios.  There is a one-to-one relationship between a 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.
-Calculators in model run with those values and produce set of outputs
-Value is saved as an instance of a variable.
+{{concepts:ScenarioManagement.jpg}}
-All variables have at least one instance
-Some variables can have multiple instances
+Key points to note:
-For a simulation run, variables must have one and only one instance
-Saved collection of instances is a scenario
+  * An instance is a value for a variable.
-Instances do not have to be used in any scenario
+  * All variables must have at least one instance.
+  * Variables can have multiple instances.
+  * For a simulation run, variables use one and only one instance.
+  * Saved collection of instances is a scenario.
+  * Instances do not have to be used in any scenario.
+  * Worksheet reflects the current set of instances being used.

whatIf? Wiki

User Tools

Site Tools

Differences

Page Tools