Tutorial 3 - Creating the model objects

Page 2 of 4

In this lesson we will create the objects required for the turnover model. In the same way as in Tutorial 2-Creating a compartment model, you will use the Matrix window to create blocks in the Interaction matrix.

Creating blocks

Open the Matrix window.
Create the following objects, by right-clicking in the matrix and selecting objects from the pop-up menu. You can see the positions of the different objects in the picture below.

Name	Type	Full name	Symbol	Image
Source	Source/Sink	Atmospheric Source		“media/Atmoshpere.jpg”
Upper_Soil	Compartment	Upper soil layer	A_Upper	“media/Soil 3.jpg”
Lower_Soil	Compartment	Lower soil layer	A_Lower	“media/Soil.gif”
Sink	Source/Sink			“sources/Drain.jpg”
Deposition	Transfer	Deposition transfer rate
Upper_to_Lower	Transfer	Perculation transfer rate coefficient
Lower_to_Sink	Transfer	Perculation transfer rate coefficient

When editing Deposition, make sure that the TC check-box in the Values tab is unchecked.

Creating parameters

Rather than specifying the initial conditions and transfer rate coefficients directly, we will create parameters for these values. This approach makes it possible to perform probabilistic analysis, sensitivity analysis and parameter optimization. It also makes it easier to enter and review the values.

Open the Blocks window. The table lists the seven blocks of the model. Enter the following value (initial condition/expression) for the Blocks. All the “Unknown values” are Parameters.

Name	Value
Deposition	“input”
Lower_Soil	“ic”
Lower_to_Sink	“TC”
Upper_Soil	“ic”
Upper_to_Lower	“TC”

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Creating vector and matrix parameters (3/4)

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Using index lists (1/4)

References