Compare the Model's Behavior to Historical Data

lynchyml · Post by **lynchyml** » Wed Sep 23, 2009 2:31 am

hello everyone!

The time range of historical data is 2000-2006, but the graph show all the values from 2000-2020.

thank you very much!

bob@vensim.com · Post by **bob@vensim.com** » Wed Sep 23, 2009 10:38 am

Use the Time Axis tab of the control panel to set the time range to view of set it directly in custom graph definitions.

lynchyml · Post by **lynchyml** » Thu Sep 24, 2009 2:59 am

thank you for your reply.

After reading chapter12 and 13, I know there are two methods to select a time range:
first: time axis tab of the controp panel as you said.
second:drag the mouse.

the problem is :
the two methods will change the time range of all varibles in the graph, but I only have to change one varible's time range.

time range of one varible is 2000-2006
time range of the other varible is 2000-2020
both the varibles will display in one graph

hoping for futher explain
thank you very much!

[Edited on 9-24-2009 by lynchyml]

Post by **Administrator** » Thu Sep 24, 2009 7:41 am

The only way I can think of doing what you want is to have the data for the 2000-2006 variable to be an external data source, and import this to a VDF file (or via Excel).

bob@vensim.com · Post by **bob@vensim.com** » Thu Sep 24, 2009 10:41 am

You should be using Data variables for data, and these will only display the available points so the graph will automatically stop when data are no longer available.

lynchyml · Post by **lynchyml** » Fri Sep 25, 2009 2:43 am

warning:simulation starts before first time for exogenous variable