Draw arrows

Analytica User Guide >

Use the arrow tool to draw or remove arrows (influences) between variable nodes. Drawing an arrow from variable or function A to B puts A in the list of inputs of B. This makes it conveniently available to select from the inputs menu when creating or editing the definition of B (see Chapter 8: Creating and Editing Definitions).

Draw an arrow: To draw an arrow, first click the arrow icon in the toolbar to select the arrow tool. In arrow mode, the cursor changes to this arrow icon when over a diagram window.

1. Drag from the origin node (which highlights) to the destination node (which also highlights).
2. Release the mouse button, and it draws the arrow.

To speed up drawing arrows from multiple nodes to a single destination, select all the origin nodes. Then drag from any origin node to the destination node. When you release the mouse, it draws arrows from all the origin nodes.

Tip

Some arrows are hidden. They do not appear even when you try to draw them. For example, by default, arrows to and from indexes and functions are not shown. You can change these settings in the Diagram Style dialog and Node Style dialog.

To remove an arrow:

• Click the arrow to select it, then press the Backspace or Delete key, or
• Just redraw the arrow from the origin node to the destination node. If the origin variable is used in the definition of the destination, it asks if you really want to remove it.

Tip

When you enter or edit a definition (Creating or editing a definition), Analytica automatically updates the arrows into the variable to reflect those other variables that it mentions (or does not mention).

Influence cycle or loop: An influence cycle occurs when a variable A depends on itself directly, where A → A, or indirectly so that the arrows form a directed circular path, e.g., A →B →C →A.

If you try to draw arrows that would make a cycle, it warns and prevents you. The exception is if at least one of the variables in the cycle is defined with the Dynamic function, and contains a time- lagged dependence on another variable in the cycle, shown as a gray arrow (see Chapter 17: Dynamic Simulation).

Arrows linking to module nodes: When there are arrows between variables in different modules, they are reflected by arrows to and from the module nodes.

Arrows between variable and module nodes are illustrated below.

Arrow from variable node to variable node:

Arrow from variable node to module node:

Arrow from module node to variable node:

How to draw arrows between different modules:

Arrow from module node to module node:

Double-headed arrow between module nodes:

Small arrowhead to the right or left of a variable node:

See Also

Creating and editing nodes <-

Drawing arrows

-> How to draw arrows between different modules