View source for Defining the fox population as a function of time

[[Category: Foxes and Hares model]]
[[Category: Definitions]]

* Double click ‘Foxes at start’ node. 

'''Expected: Object window should appear.'''

* In the Description field type ‘The fox population at the start of each time period’.
==Expression Assist==
Use the Expression assist to set the definition:= Dynamic(6,Foxes_at_end[Time-1]*(1+Fox_birth_rate))
*Select definition
*Enter 'D
'''Expected: the expression assist offers possible entries starting with D'''
*Enter 'y'
'''Expected: The list truncates to only include those starting with DY'''
*Use the down arrow to select Dynamic and tab to select it
'''Expected: Dynamic( in the definition'''
*Enter 6,
'''Expected, Expressions Assist moves to the next parameter. '''
*Continue using the expression assist to enter the definition as depicted.

:[[Image:Foxes at start object.jpg]]

* Double click ‘Foxes at end’.

'''Expected: Object window should appear.''' 

*. Type ‘The fox population at the end of each time period’ in the Description field.

* Click the Definition field.  Click ‘Inputs’ popup menu button, select ‘Foxes_at_start’. 

:[[Image:Foxes at end.jpg]]

* ‘Foxes_at_start’ should appear on the Definition field. Click on the check button to accept your entry. Click on the diagram button.

:[[Image:Foxes at end 1.1.jpg]]

* With the Foxes at end node selected, click on the result button. Result window should appear.

:[[Image:Result Foxes at end.jpg]]

==See Also==
* [[Tutorial: Dynamic system model]]
* [[Creating the Foxes and Hares model (based on chapter 7 of tutorial)]]