Editing Attributes

Each operator and each algorithm (and even the connections between operators) carries a number of properties/attributes (both terms are used interchangeable). These attributes can be simple ones like a number (i.e. the mutation probability in a mutation operation) or arrays of arbitrary complex objects. As of version 0.5.1 there's a special view in which which you can edit these attributes (see below for a picture of the view, showing the attributes of an algorithm). The view can be activated via choosing Window > Show View > Properties. The attributes of an object are shown in the view by selecting the object (operators and connections). To see the attributes of the algorithm itself just click into an empty area in the algorithm area.
The attributes view consists of three columns: name, type and value. The name and the value are self-explainatory, in contrast to the type.

Each attribute of a different type can be edited in a different way, so the type itself is an indicator of how edit the value of an attribute. There are different types of attributes, see the table below:

empty The attribute is read-only and cannot be edited.
B Binary type; the value can be edited by clicking the value field.
C Class type; clicking the small button to the right of the value field will open a dialog which shows classes that can be used as a value for this attribute. Choosing a class will create an instance of that class and assign the newly created object as the value of the selected attribute.
D Directory type; the button in the value filed lets you choose a directory in the local file system.
F File type; the button in the value filed lets you choose a file in the local file system.
S String type; the value of the attribute can be entered directly into the value field. This is valid for all primitive data types, like strings, integer numbers, float numbers etc.
[?] Array type; the value may be edited by using the buttons in the headline of the attributes view, which allow you to add and remove items from/to arrays. The children of such a value can be edited just like described in rows above in this table.
[S] String-like Array type; this is a special case of the array type which can also be edited by entering a value directly. Such an array always starts/ends with curly braces and separates the array items with commas. Example: to enter an array consisting of the three integer numbers 1, 2 and 3 just enter {1,2,3}.

Arrays can be edited by using the four buttons. The buttons 1 and 2 only become enabled when selecting an array property. They allow you add and remove items from/to an array. A new array will be created when adding an item to a selected attribute which has the value NULL. Both buttons always add an item to the beginning of the array (position 0) resp. remove the first item from the array. Buttons 3 and 4 become enabled when an item in an array is selected. Button 3 inserts an item AFTER the currently selected item. Button 4 remove the selected item.

All four buttons also work with arrays of arrays (hopefully also with n-dimensional arryays). Please note that an item in an array cannot be edited (is marked read-only) if the array property itself is read-only.

In addition to the four buttons already described, there are three more. The button next to the four buttons used for array handling resets the attribute. Resetting the value of an attribute means the value is set to NULL resp. to 0, depending on the type of the attribute. The last two buttons hide read-only attributes resp. attributes that carry the expert flag.