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Instructions for using the symbol info tool

Within the /dcs/emp/empublic/teaching/cs405/UsingEMPE directory, you can find the syminfoBeynon2011 subdirectory. Executing the run.eden file within this subdirectory using tkeden launches a basic tool that can be used to explore and record observables within any model that has been loaded into the same environment.

The tool supplies an interface through which you can record information about observables in a construal.

Each observable that is recorded has an assigned "observable index" (though this is not necessarily fixed and may change when an observable is deleted). There must always be at least one observable entry at all times, but an observable can be spurious (i.e. it doesn't have to be present in the model).

To record an observable, you must first know the NAME of the observable as it is represented in Eden (so for instance the Donald observable door/hinge is represented in Eden as _door_hinge etc and a component of an Angel observable such as pres_scoutbox.height is represented in Eden as pres_scoutbox_height).

The red entries in the display are intended to be edited by the modeller. You record an observable by entering its name into the NAME field, and entering an informal natural language characterisation of the observable into the INFO field. When you then press the "Add observable" button, the current definition and value of the observable (as specified by dependencies in Eden) will be displayed in the DEFN and VALUE fields.

The modeller is not intended to edit the entries in the DEFN and VALUE fields directly. Should you inadvertently interfere with the text in these fields in any way (e.g. by clicking in these fields), the dependency linking these fields to the the observable name is broken. To restore the dependency, you should click the "Refresh observable" button.

You can add the same observable more than once, either by accident, or in order to refine the information recorded about an observable. You can use the "Delete observable" button to remove redundant entries.

You can cycle through the observables recorded by using the "Next observable" and "Previous observable" buttons. If you know the observable number for a specific observable of interest, you can access it directly by setting 'currentindex' to this number.

Two Eden lists of strings are used to store the information that is recorded. These lists are called listobs and listinfoobs. They have the same length, and the i-th entry in these lists are the name and the description of the i-th observable respectively. To ensure that the information you gather about observables is stored after your interaction with the tool terminates, you should copy the values of these two lists to a file. To resume the recording process, you can then use the recorded values to assign initial values to listobs and listinfoobs and load these values when you later start-up the tool with the same construal. For instance, in the basic start-up configuration the initial values of listobs and listinfoobs are set up as follows:

listobs = ["listinfoobs","listobs"];
listinfoobs = ["The list of descriptions of recorded observables","The list of names of recorded observables"];

There are two Eden observables that can be used to change the font in the display: these are fontname and fontsize.
The default settings of these observables are:

fontname = "Arial""; fontsize = 12;