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Working with model diagrams : Changing labels

Changing the label for elements on a model diagram

To re-label any element in the model diagram:

  1. Click on the select tool on the toolbar.
  2. Select an element in the model diagram, or a group of elements whose labels you wish to change.
  3. Click on the label of a selected element to change it, or drag across the label to select some text for cut/copy/delete.
  4. Use the Backspace or the Delete key to remove the existing label.
  5. Type in the label you wish for this model element. You can use any characters from the keyboard, including spaces, capital letters, the RETURN character and special characters, except for the period ( . ), the forward slash ( / ) and the reverse slash ( \ ).

If you try to change a label to one that already exists in the same submodel, or you use illegal characters in the label, or only use whitespace in the label so it cannot be seen, then Simile will generate an error message and leave the label unchanged. However any label is allowed for a T text element.


  • Using the RETURN character is a good way of avoiding having long labels that stretch across the model diagram.
  • You should choose labels that to some extent make the model diagram self-documenting: someone who is knowledgeable about the subject area of the model should be able to read the diagram and have a good idea of what most of the labels mean.
  • However, remember that the labels are (by default) the names of the variables used in equations. Therefore, you should avoid labels that are too long and wordy. (You can however provide your own local names for variables inside equations, so you can use long labels if you prefer.)
  • Remember also that the full label for an element in the model diagram is the label that you give it, along with the labels of any submodel(s) that it is enclosed within. (This is just like file names: the name of a file is the name given to it, along with the names of all the directories it is enclosed within.) Therefore, if you have a biomass compartment in each of two submodels - say "animal" and "plant" - then it is quite acceptable to label each of the two compartments with the same label, "biomass", since one is "plant/biomass" and the other is "animal/biomass".
  • Choose names that reflect the type of element that you are re-labelling: see below.

Appropriate types of label for different types of model element


The label should reflect the fact that this is (usually) referring to an amount of something. Thus, use terms like biomass, area or numbers.


The label should reflect the fact that the a flow is (usually) some process. Thus, use terms like production, growth, reproduction.

Simple submodels

The label should reflect the subsystem being modelled, for example, "vegetation".

Multiple-instance submodels (fixed-membership and population submodels)

The name should reflect one instance of the type represented by the submodel. Thus:

  • if you are modelling a stand of trees, then the submodel should be called "tree";
  • if you are modelling an area as multiple patches, then the submodel should be called "patch";
  • if you are modelling multiple size classes, then the submodel should be called "size-class".

i.e. use the singular, not the plural. The reason for this is that the submodel represents a single individual: the fact that there is a set of them is indicated by the appropriate setting in the Properties box for the submodel: it is not an intrinsic property of the submodel itself.

Association submodels

The label should reflect the type of association that exists between the two types of object involved in the relation. Thus:

  • if the association submodel represents ownership between people and patches of land, then label it "ownership";
  • if the association submodel represents the fact that some spatial units are next to others, then label it "next to".

Role arrow

The label should reflect the role of the object in the association. Thus, if the association submodel is used to represent ownership of patches of land by people, then the role arrow coming from the person submodel should be labelled "owner", and the role arrow coming from the patch submodel should be labelled "owned".

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