A compartment is a block that acts as an integrator of quantities of materials in a model. The quantity held within this block is calculated with a differential equation, where the input and output rates are defined by the transfer blocks.
Note that the compartment block is only available with the ODE toolbox.
Creating a compartment
From the Projects window
Expand the Project to which you wish to add the compartment by clicking the + symbol next to it. Right-click on ‘Blocks’, or a sub-system
in ‘Blocks’, and select Compartment
from the pop-up menu.
From the matrix window
From the Blocks window
Editing a compartment
|Note||Most block properties can be edited directly in the blocks window.
The block editor is shown by right-clicking the block in a window and selecting Edit. In the Blocks window, you can also show the block editor by selecting the block and clicking the button, or by double-clicking the right-most “validation” column of the block.
The block editor has three tabs:
This page lets you edit basic properties such as name, sub-system and base unit. See editing properties for more information.
This page lets you specify initial conditions and other index specific properties. See Editing values for more information.
Dimension - You can specify the dimension of the block by using the Type drop down list. Depending on the dimension the index drop down lists are activated.
- For blocks that are non-scalar, the first columns will specify indices from the index lists
. This allows you to specify different expressions for different indices. The top row is named “default” and can be used when the same value should be set for all indices.
- Allows you to enter an expression for the initial inventory of the corresponding material. Note that a value, a parameter or an Expression
in the initial condition is evaluated when the simulation is started and time = t0. The Expression editing tool
is available to help the user to enter and edit data.
dy/dt - Lets you add extra term to the differential equation of the compartment. This feature is useful, for instance, for a simple integration of values where it is not logical to modify the state of the compartment through transfers.
Non-negative – If set, the inventory of the compartment cannot be negative. Default = “disabled”
Abs. error tol.– Sets the absolute error tolerance for the given material. If empty, the “global” value set in simulation settings is used. Default =
- By using the Table control button
you can display more columns that will help you document your model.