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Bayesian Networks UDF


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This set of functions deals with interacting with Bayesian Networks or Influence Diagrams built (or exported) with GeNIe. Bayesian Networks are another awesome computational tool that allow you to create a graphical model of a system or problem and get intelligent results from it, making predictions, inferences, or assumptions based on available evidence, formulas, and probabilities. I'll go into potential uses later in the post.

IMPORTANT: You'll need the ActiveX component from here:


Once you've downloaded it, unzip SmileX.ocx it to a directory like c:/SmileX, then you'll need to register it.

Press Windows Key + R, then type in regsvr32 c:/SmileX/SmileX.ocx

(win7/Vista users, let me know what the equivalent is if it's changed?)

Now you need the UDF and a sample bayesian network:


Here's a demo script. It guesses what animal you're thinking of after you select the characteristics from the drop-down menus.

#include <ComboConstants.au3>
#include <GUIConstantsEx.au3>
#include <ProgressConstants.au3>
#include <StaticConstants.au3>
#include <WindowsConstants.au3>
#include <Array.au3>
#include "_SmileX.au3"

$Form1 = GUICreate("Form1", 436, 226, 192, 124)
$Progress1 = GUICtrlCreateProgress(264, 24, 150, 17)
$Progress2 = GUICtrlCreateProgress(264, 56, 150, 17)
$Progress3 = GUICtrlCreateProgress(264, 88, 150, 17)
$Progress4 = GUICtrlCreateProgress(264, 120, 150, 17)
$Progress5 = GUICtrlCreateProgress(264, 152, 150, 17)
$Label1 = GUICtrlCreateLabel("Monkey", 208, 24, 42, 17)
GUICtrlSetColor(-1, 0xFFFFFF)
$Label2 = GUICtrlCreateLabel("Penguin", 208, 56, 43, 17)
GUICtrlSetColor(-1, 0xFFFFFF)
$Label3 = GUICtrlCreateLabel("Platypus", 208, 88, 44, 17)
GUICtrlSetColor(-1, 0xFFFFFF)
$Label4 = GUICtrlCreateLabel("Robin", 208, 120, 32, 17)
GUICtrlSetColor(-1, 0xFFFFFF)
$Label5 = GUICtrlCreateLabel("Turtle", 208, 152, 31, 17)
GUICtrlSetColor(-1, 0xFFFFFF)
$Combo1 = GUICtrlCreateCombo("Environment", 32, 24, 145, 25)
$Combo2 = GUICtrlCreateCombo("Body Covering", 32, 56, 145, 25)
$Combo3 = GUICtrlCreateCombo("Warm Blooded", 32, 88, 145, 25)
$Combo4 = GUICtrlCreateCombo("Has Shell", 32, 120, 145, 25)
$Combo5 = GUICtrlCreateCombo("Bears Young", 32, 152, 145, 25)
$Combo6 = GUICtrlCreateCombo("Class", 32, 184, 145, 25)
$Button1 = GUICtrlCreateButton("Clear All Evidence", 280, 184, 123, 25)

GUICtrlSetData($Combo1, "Air|Land|Water", "Air")
GUICtrlSetData($Combo2, "Hair|Down|Scales", "Hair")
GUICtrlSetData($Combo3, "True|False", "Warm Blooded")
GUICtrlSetData($Combo4, "True|False", "True")
GUICtrlSetData($Combo5, "Eggs|Live", "Eggs")
GUICtrlSetData($Combo6, "Bird|Mammal|Reptile", "Bird")

$mySmileX = ObjCreate("SMILEX.SmilexCtrl.1")
_SmilexCreateNetwork($mySmileX, "Animals.dsl")
While 1
    $nMsg = GUIGetMsg()
    Switch $nMsg
        Case $GUI_EVENT_CLOSE
        Case $Combo1
                $mySmileX.SetEvidence("Environment", GUICtrlRead($Combo1))

        Case $Combo2
            _SmilexSetEvidence($mySmileX, "BodyCovering", GUICtrlRead($Combo2))
        Case $Combo3
            _SmilexSetEvidence($mySmileX, "WarmBlooded", GUICtrlRead($Combo3))
        Case $Combo4
            _SmilexSetEvidence($mySmileX, "HasShell", GUICtrlRead($Combo4))
        Case $Combo5
            _SmilexSetEvidence($mySmileX, "BearsYoungAs", GUICtrlRead($Combo5))
        Case $Combo6
            _SmilexSetEvidence($mySmileX, "Class", GUICtrlRead($Combo6))
        Case $Button1

Func _UpdateGuess()
                    _SmilexUpdateBeliefs($mySmileX, "Lauritzen")

                    $aResult = _SmilexGetBeliefs($mySmileX, "Animal")
                    GUICtrlSetData($Progress1, $aResult[0]*100)
                    GUICtrlSetData($Progress2, $aResult[1]*100)
                    GUICtrlSetData($Progress3, $aResult[2]*100)
                    GUICtrlSetData($Progress4, $aResult[3]*100)
                    GUICtrlSetData($Progress5, $aResult[4]*100)

Ok, so Bayesian Networks are a way of using probability, evidence, and math to make intelligent inferences from a system. You see them used a lot in forensics, economics, law, military, medicine, and a ton of other real-world applications. What makes them useful is their near universal applicability. The system can be used to model almost anything.

You could, for example, create a model of World of Warcraft gameplay, then use AutoIt to plug in knowledge(values from the game) and interface with the game (keystrokes, mouse movement.) These networks are the ideal in Model - View - Controller system design, because they're inherently restricted to the Model aspect, and leverage a lot of computational power by abstracting the algorithms used in Model design. You don't get the view and controller mixed up in the Model, so you can do a lot more kung-fu with the Model design.

Here's some sample networks. They're not really useful for anything we on the forum would need, except maybe the win98 printer troubleshooter system. However, if you download GeNIe 2 and look at them, you can get a feel for how complicated networks are put together, by using expert opinion, real world statistics, and mathematics.

You're required to contact http://genie.sis.pitt.edu/license.html the developers before using SmileX in a commercial application.

It seems complicated at first, but by using some of the simple models (like the Animals guessing game) you get a feel for what's going on. These networks formalize the abstraction of the system you're modeling, and allow you to focus on development of the model, once your interface is complete.

The networks are also useful because they can provide you with a probability for a scenario. In the demo script, you'll notice that occasionally the bars will display less than 100% full, because the network believes in the options to varying degrees. Once you've provided enough information, though, the selection resolves and it displays exactly the animal with the characteristics you chose. In scenarios where you don't have complete information, however, you can direct the system to continue based on the most probable selection, and you have a clear and justifiable reason for the choice. Doctors often use these networks for diagnosis.

Here's the COM object documentation:




Screenshots of Networks in action:


And last, but definitely not least, the GeNIe documentation, with tutorials and lots of background knowledge.


Good luck!

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