Connect nodes Adds edges from all “First-selected” nodes to all “Second-selected” nodes. Note that the direction of the edges is independent of the current selection mode. The arrows on the edges will always point from the “First-selected” ones to the “Second-selected” ones. If any of these selections is empty, clicking the toolbar button will have no effect at all. By selecting groups of nodes in each selection mode, multiple edges may be created with a single command. If, e.g., N nodes are “First-selected” and M nodes are “Second-selected”, then the “Connect nodes” command will produce N times M new edges. Instead of clicking the “Connect nodes” button in the toolbar, you may alternatively select “Connect nodes” from the “Model” menu. Nodes may also be connected by selecting one node or a group of nodes and dragging them to the goal node. Release the mouse button when the goal node becomes hilited. To delete edges, you just repeat the same procedure you used to create the edges. Thus, if e.g., there is an edge from Node 1 to Node 2, you can delete this edge either by selecting the nodes with the appropriate selection modes and using the “Connect nodes” button, or by dragging Node 1 onto Node 2. To change the direction of an edge, simply create a new edge with the desired direction by one of the above methods. The old edge will automatically be deleted. Note that if you change the direction of an edge, all edge function data is lost. Thus, if the old edge contained an edge function, and you want the reversed edge to have the same function settings, you need to reenter this in the “Edit edge” dialog box. This button is only present in the “Graphical view toolbar”.