AXTut BuildNet

From Emergent

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Contents 1 Building a Network 2 Manipulating the 3d View 3 Configuring the Network View 4 Changing the Network Configuration

Building a Network

The Wizard makes it easy to get started making a network. It is located in the wizards section of the browser, and can always be found in the LeabraWizard_0 tab at the top of this middle panel.

You will see that it is currently configured for 3 layers, which is fine for our purposes. But how do we tell it how big to make these layers? The wizard has some layer configuration information tucked inside of it -- to access it, you need to open up the wizard object in the browser (as is true of most things in this simulator). This link: .wizards.LeabraWizard_0.layer_cfg.Input will take you directy to the configuration information for the Input layer. You can see the browser expanding to reveal the other layer configuration information as well. Here are the layer sizes (n_units) you should enter:

• Input = 6
• Hidden = 16
• Output = 2

Note that the system automatically applies changes when you move from one selection to the next.

Next, return to the LeabraWizard_0 tab, and at the bottom, click the Network menu button, and choose the Network/StdNetwork option. This pops up a confirmation dialog explaining that it will create a new network according to your current specifications. Hit OK.

You will see a network appear in the right (Viewer) panel, and the left browser will expand to reveal all of the objects created (e.g., layers and specifications). Feel free to click around on these objects now to see what they have in them -- we will just use the defaults so there is no need to change anything.

Now we'll move on to making the AXTut InputData for the simple target detection task. Below are a few optional topics that you can explore if you wish (or come back to later at any time):

Manipulating the 3d View

There are different modes and controls for the 3d view located on the extreme right-hand side of the window next to the network display. Drag the mouse over them to see what they do (a "tool tip" should pop up when the mouse hovers over the button).

To begin, you can experiment with the "hand" tool -- if you click the mouse and move it around, you'll see that you can manipulate the "camera view" into the 3d view of the network.

Two key tips:

• Hold down Shift (while moving the mouse) to move instead of rotate.
• Pressing the "home" icon restores the initial view (this is the first home one, not the blueprint guy -- the blueprint guy is for saving the current view state as the default view that the home button returns to.

At some point you'll discover that if you don't completely stop before lifting the mouse button, the view continues to rotate -- kind of mezmerizing. Apologies if you spend too much time doing this (we certainly have.. :). Just click in the window to stop.

If you have a scroll wheel on your mouse, you'll see that it acts like a zoom. The same effect can be had with the Dolly wheel on the bottom right of network view (the term is an analogy to a camera dolly that moves a camera through a scene in filming a movie).

The Rotx and Roty wheels rotate precisely around the x and y axes -- these are often more useful than the mouse-based rotation because they don't introduce off-angles.

The Flashlight button is very useful for zooming in on something of interest (especially for large complicated displays) -- after clicking on it, then click on an object in the view (NOTE: text doesn't work for this purpose). This button stays on until unclicked or another button is clicked, so you can do repeated exploration.

Finally, for extra thrills, you can click the right mouse button (or ctrl+mouse on a Mac) and configure many interesting display options -- check out the different still draw styles, and the stereo options -- dig out those old red/green stereo glasses!

Configuring the Network View

The middle (Edit) panel tab labeled Network_0 provides various parameters for controlling the network display. There are 3 main segments

(see the wiki Network_View page for more info):

• Display parameters at the top (font sizes, display style etc) (mouse over to get more info, and explore!)
• Network variable selector -- what value to display in the units in the network view (activations vs. weights vs. netinputs etc). If you select one of the weight variables (e.g., r.wt for receiving weights into a selected unit; s.wt is for sending weights out), you then need to use the red arrow tool in the viewer to select a unit to view -- it will turn green, and you should be able to see its weights.
• Spec selector and viewer -- this is very handy for seeing where your specs are used in the network -- try clicking on the HiddenLayer and then Input_Output -- note that the green layer border changes color indicating which layers are using these layer specs. You can also use the context menu to edit the specs right there.

Changing the Network Configuration

You can also configure the network layout interactively in the Viewer (right panel), including repositioning the layers, and orienting the network display relative to other objects in the view (which we postpone for later, when this arises).

To reposition layers, select the red arrow tool, and you'll see that transparent purple arrow objects now appear on the layers, and a fancy box thing appears on the network text box. These are the manipulation controls. Try clicking on one of the horizontal arrows for the Output layer, and moving it around. This moves within the "horizontal" plane (the X-Y plane for the network). The vertical arrows not surprisingly move in the vertical dimension (the Z axis for the network).