delay3 is the system dynamics function that returns a third order exponential delay of the input. If the delay time changes, the input is preserved. 

The plot below illustrates how the function works (initialValue=0.0; delayTime=5.0): 

delay3 can be called in formulas of system dynamics variables.

delay3 function has two notations:

input can be a flow variable, or a numeric expression of any complexity.

delayTime can be either a constant or a numeric expression (e.g. a function call, or a numeric parameter). It should return a positive number:  delay3 function with zero or negative delay time returns not a number. 

The simplified notation of the function. Is used when the initial value is zero.


input -> units
delayTime -> time
initialValue -> units

delay3() -> units

The output units are the same as the input ones.

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