Palette

This window allows you to select tools for drawing in the Main Window.

Below, we will refer to the colored rectangle to the right of the paint brush icon as the Palette swatch. To change the color of this swatch, one can

• double-click the swatch, or
• use the Choose Color... item of the Edit menu, or
• use the Copy Color tool of the Palette.

Select

When this tool is selected:

You can select or unselect any number of nodes or arrows of the graph displayed in the Main Window.

A selected node is indicated by four red dots surrounding it; a selected arrow by two red dots.

Clicking on any node or arrow toggles its selection status between selected and unselected.

Clicking on any node or arrow while holding down the OPTION key selects all the nodes and all the arrows of the graph. Alternatively, you can press Select All in the Edit menu to select all nodes and arrows. (But note that if one of the text boxes below a node is currently active, then pressing Select All in the Edit menu will instead select all the text in the text box.)

Call a non-graph point of the Main Window any point that is not part of any node or arrow of the graph.

Clicking on any non-graph point of the Main Window while holding down the OPTION key unselects all the nodes and all the arrows of the graph.

Let [A,B] be the rectangular region of the Main Window with points A and B as opposite (top-left and bottom-right) corners. If

• you press the mouse button down when the cursor is at non-graph point A of the Main Window, and
• while holding the mouse button down, you move the cursor to point B of the Main Window, and
• you release the mouse button,

then all the nodes and arrows within [A,B] will be selected.

Drag

When this tool is selected:

If

• you press the mouse button down when the cursor is over a selected node or arrow of the Main Window, and
• while holding the mouse button down, you move the cursor,

then the selected parts of the graph will move as the cursor moves, and will continue to do so until you release the mouse button. The unselected parts of the graph will not move.

Open

When this tool is selected:

If run-state = initial, then double clicking on any node will open the Node Prior-Info. window.

If run-state = intermediate or final, then double clicking on any node will open the Node Probs. window.

When Palette is Closed

When you close the Palette, the cursor becomes a "pointer"—a bold-face arrow pointing towards the top-left corner of the screen. This cursor performs the first 3 Palette operations: selecting, dragging and opening. When the Palette is open, to go from selecting to dragging, you must first de-select the selection tool and select the dragging tool. When the Palette is closed, you can go from selecting to dragging continuously, without doing any intermediate steps. Thus, when the Palette is closed, you get a pointer cursor that behaves like it does in drawing applications such as MacDraw. More specifically, it behaves as follows:

• If you click on a node or arrow, then
  • if the node or arrow clicked on is initially in the selected state, then nothing happens—all nodes and arrows retain their previous selection status.
  • if the node or arrow clicked on is initially in the unselected state, then everything is unselected except for the node or arrow clicked on, which is selected.
• If you click on a non-graph point of the Main Window, then everything is unselected.
• If, while holding the SHIFT key down, you click on a node or arrow, then
  • the node or arrow clicked on has its selection status toggled between selected and unselected.
  • the other nodes or arrows that were not clicked on retain their previous selection status.
• If, while holding the SHIFT key down, you click on a non-graph point of the Main Window, then nothing happens—all nodes and arrows retain their previous selection status.
• Let [A,B] be the rectangular region of the Main Window with points A and B as opposite (top-left and bottom-right) corners. If
  • you press the mouse button down when the cursor is at non-graph point A of the Main Window, and
  • while holding the mouse button down, you move the cursor to point B of the Main Window, and
  • you release the mouse button,

  then all the nodes and arrows within [A,B] will be selected.

• Same behavior as when Drag tool is selected.
• Same behavior as when Open tool is selected.

Rotate

When this tool is selected:

Clicking once on any beam-splitter node will rotate its icon clockwise by 15 degrees.

Paint

Custom Nodes are initially created white and Deterministic ones black. However, you may change this:

When the Paint tool is selected:

Clicking on any Custom Node or Deterministic Node will paint the node in the color of the Palette swatch.

Copy Color

When this tool is selected:

Clicking on any Custom Node or Deterministic Node will paint the Palette swatch in the color of the node.

Draw Arrow

When this tool is selected:

If

• you press the mouse button down when the cursor is over a node, and
• while holding the mouse button down, you move the cursor so that it lies over another node, and
• you release the mouse button,

then an arrow will be draw from the first to the second node.

Change Source Node of Arrow

We will say that two nodes X1 and and X2 are compatible  if they:

1. Have the same number of states,
2. These states have the same names,
3. These names are listed in the same order in the Node Prior-Info. windows of nodes X1 and X2.

Consider 3 nodes X1, X2 and Y such that X1 and X2 are compatible and there is an arrow going from X1 to Y (X1->Y  X2 ). Suppose you wish to change the arrow's source node from X1 to X2 (X1  Y<-X2 ). You could accomplishing this task in 2 steps, by first deleting the arrow from X1 to Y, and then drawing a new arrow from X2 to Y. But the first of these steps would destroy the transition matrix of Y. That's because the number of columns of this matrix depends on the number of arrows entering Y. The Change Source Node of Arrow tool allows you to accomplish this task in a single step that preserves the transition matrix of Y.

When this tool is selected:

If

• you press the mouse button down when the cursor is over an arrow from node X1 to node Y, and
• while holding the mouse button down, you move the cursor so that it lies over another node X2 which is compatible with X1, and
• you release the mouse button,

then the arrow from X1 to Y will be replaced by an arrow from the X2 to Y. The transition matrix of Y will remain unchanged throughout this process.

Popup for Selecting a Node Tool

This popup allows you to choose a tool that will draw a particular type of node.

Clicking at any point of the Main Window will draw a node of that type, centered at the click point.

[Table Of Contents]