In order to structure a model, we first need to decide which type of model we wish to structure and then select a particular one out of the existing ones.
In top menu of the MODEL tool we may either click on the Individual Models button in order to structure an individual model, the Group Models button in order to structure a group model, or the Overall Model button in order to structure an overall model. These buttons will either be enabled or disabled depending on the dependencies between the models (ex. a group model may be structured only when all the individual models beneath it have been completed).
Upon selecting the type of model that we wish to structure, the model panel opens below. Depending on the type of model, at the top of this panel we may select a particular model.
Below the model selection part of the interface we have two buttons that are used to switch between structuring the model and tuning its parameters. Tuning the parameters of the model requires that the structuring of the model is completed and a multi-criteria layer is created. Therefore, tuning the parameters will only become available once this layer is constructed.
The structure of a model is divided into 3 parts:
Intermediate data may be added, edited or deleted from the Intermediate data panel using the Add, Edit and Remove buttons.
Intermediate data are of two types: constructed and distance.
Constructed intermediate data are used to construct a single indicator from one or several pieces of data using any type of logic that can be transcribed into an algorithm. Within the MODEL tool we may input a name for the intermediate data, a description, its type as either constructed or distance and in the case of the first type it construction rule as seen below.
In the above example we have illustrated how a numerical piece of input data may be transformed into an ordinal intermediate data.
When a single piece of data is referenced in the construction rule, then the intermediate data will contain the same features as the input data only with a new attribute that is constructed using this rule. When several pieces of data are references, then the features are broken down so that each feature will contain a single value for each different piece of data.
Distance intermediate data are used to in order to alter the geometry of a single piece of input data. Within the MODEL tool we may input a name for this intermediate data, a description, its type, a distance parameter and its unit of measure (m, km or Nq), the input data that is used and a condition in order to select the features that will be used.
The resulting distance intermediate data will contain only the features selected by the filtering condition which have been buffered with the input distance. These features are merged together if they intersect and are given as attribute the value "in". Another set of features is constructed from cutting out the buffered features from the project bounds (which were constructed after selecting the input data). These features are given as attibute the value "out".
Filters may be added, edited or deleted from the Filters panel using the Add, Edit and Remove buttons.
Filters are of two types: inside or outside. A filter may be used to select a set of features from one piece of input data or intermediate data and keep only the decision map that overlaps with these features (filter inside), or cut them away from the decision map (filter outside).
None: At the moment only a single piece of sata may be used inside a filter, while the decision map is filtered using a disjunction operator (OR) between all the different filters. We plan to add the functionality of allowing a filter to reference several pieces of data in it selection rule so that a conjunction operator (AND) may also be simulated.
Criteria may be added, edited or deleted from the Criteria panel using the Add, Edit and Remove buttons.
Criteria are identical to the constructed intermediate data with the exception that they can use in their construction rules the intermediate data and that a direction or preference on the values of the criterion also need to be set.
Once all the intermediate data, filters and criteria have been defined, we may construct the multi-criteria layer using the Build Multi-Criteria Layer button at the bottom of the MODEL interface.