Please refer to reference section 3.7

The KnowledgeFlow interface is composed of three main areas. There are main action buttons on the left, the object selection area and finally the layout area. We shall look at each in turn.

Left Action Buttons

The picture show the action buttons available on the top left of the interface window. The top button sets the mouse into a select/modify mode. In this mode, objects can be moved around and manipulated with the mouse.

The button below it allows the user to save the experiment setup to a file. The next button is used to load up previously saved experiment setups. Lastly, the stop button is used to stop a running experiment.

Object Selection

The Object Selection area is located on the top part of the interface window, next to the action buttons we just looked at. This area serves as a toolbox where the user will pick objects to add to the experiment layout. Objects are grouped into 7 categories and they are Evaluation, Visualization, Filters, Classifiers, Clusterers, DataSources and DataSinks.

Each category is located on a single tab and a user can switch categories by clicking on the tab at the top and proceed to select the desired object to add. Objects are added to the experiment layout by first left clicking on the desired object and then left clicking on an empty area in the layout.

The Experiment Layout

The layout area is the largest part of the KnowledgeFlow interface window. It is here that the experiment is laid out and controlled. It is useful to think of this area as a canvas where the experiment will be drawn out.

As described before, a user will click on an object to select it and then clicks here to place it on the layout. Some objects have user definable configuration options. Once an object has been placed on the layout, its configuration can be accessed by right clicking on it and from the menu that pops up select ‘Configure’.

Different options require different kinds of input(s) and produce different types of outputs. These inputs and outputs are controlled via connections. A connection is displayed as an arrow going from one object to another.

The picture on the left shows a connection from the datasource object ‘CSV Loader’ to the filter object ‘Discretize’. It is an active connection indicated by the red color of the arrow, and it is of type ‘dataset’. A dataset connection passes a dataset from one object to another. In this case, the loaded CSV file is passed to the filter object.

Certain objects can only accept certain types of connections as input and provide only certain types of connections as outputs. In the example above, a filter object will only accept a single dataset type connection as input. Output connections are also limited in the types of connections they can offer, but in general are not limited in the number of connections. Therefore, a datasource object can offer an unlimited number of dataset type connections as long as there is an object that can accept it.

Right clicking on an object will bring up a menu and from here, its possible connections will be listed. Clicking on a connection from the menu will create an arrow and this arrow will follow the mouse until the user left clicks on the desired destination object. When this is done, the arrow will point to this object.

Objects that are ready to receive a connection of the type and from the particular source object will have markings as shown on the picture right. The blue diamond shapes on the four corners indicate that this object is ready and willing to accept the connection.

Lastly, deleting an object is also done by right clicking on an object and from the menu and selecting delete. This action will also delete all connections to and from this object.

Status Pane

This is found in the bottom section of the interface and it displays the status of a running experiment. Details of the experiment as it runs or has completed are accessed by clicking on the Log button on the bottom right. There is a bug in this version of Weka where the status does not indicate that an experiment has finished; also, the Log window does not display details of the experiment, as it should.