Below is an example VB program that does the same thing as the "Demo" program that ships with Netica C-API. There is a Visual Studio project for it, called "Netica Demo for VB" within the " Netica\Netica xxx\Programming Examples " folder of the Netica download package. (more info on programming Netica in VB)
Sub Main()
On Error GoTo Failed
Dim app As Netica.Application |
app = New Netica.Application |
app.Visible = True |
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Dim net_file_name As String |
net_file_name = System.AppDomain.CurrentDomain.BaseDirectory() & "..\..\..\ChestClinic.dne" |
Dim net As Netica.Bnet |
net = app.ReadBNet(app.NewStream(net_file_name)) |
net.Compile() |
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Dim TB As Netica.BNode |
TB = net.Nodes.Item("Tuberculosis") |
Dim belief As Double |
belief = TB.GetBelief("present") |
MsgBox("The probability of tuberculosis is " & belief) |
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net.Nodes.Item("XRay").EnterFinding("abnormal") |
belief = TB.GetBelief("present") |
MsgBox("Given an abnormal X-Ray, the probability of tuberculosis is " & belief) |
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net.Nodes.Item("VisitAsia").EnterFinding("visit") |
belief = TB.GetBelief("present") |
MsgBox("Given abnormal X-Ray and visit to Asia, the probability of tuberculosis is " & belief) |
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net.Nodes.Item("Cancer").EnterFinding("present") |
belief = TB.GetBelief("present") |
MsgBox("Given abnormal X-Ray, Asia visit, and lung cancer, the probability of tuberculosis is " & belief) |
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net.Delete() |
If Not app.UserControl Then |
app.Quit() |
End If |
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Exit Sub |
Failed: |
MsgBox("NeticaDemo: Error " & (Err.Number And &H7FFFS) & ": " & Err.Description) |
End Sub |
Below is an example that reads in a net from the Examples folder (you may have to change the path), then reads in cases and does belief updating.
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Sub Main()
On Error GoTo Failed
Dim app As Netica.Application |
app = New Netica.Application |
Dim casefile As Streamer |
Dim net As Bnet |
Set netfile = app.NewStream("C:\Netica Data\BNs\Car_Diagnosis_0_Learned.dne") |
Set casefile = app.NewStream("C:\Netica Data\Cases\Good Cases\Car Cases 10.cas") |
Set net = app.ReadBNet(netfile) |
net.AutoUpdate = 1 |
net.Compile |
Dim lights_node As Bnode |
Set lights_node = net.Node("Lights") |
Dim lights_dim As Long |
lights_dim = lights_node.GetStateIndex("dim") |
Dim id As Long |
Dim fr As Double |
Dim caseposn As Long |
Dim done As Boolean |
done = False |
caseposn = FirstCase |
Do |
net.RetractFindings |
net.ReadFindings case_posn:=caseposn, stream:=casefile, IDNum:=id, freq:=fr |
net.ReadFindings case_posn:=caseposn, stream:=casefile, nodes:=net.Nodes, IDNum:=id, freq:=fr |
If caseposn = NoMoreCases Then |
done = True |
Else |
MsgBox "Belief in Lights dim = " & lights_node.GetBelief(lights_dim) |
End If |
caseposn = NextCase |
Loop Until done |
net.Delete |
Exit Sub
|
Failed: |
MsgBox "Error " & ((err.Number And &H7FFF) - 10000) & ": " & err.Description |
End Sub |
===============================================================================
EXAMPLES ON HOW TO SET CPT TABLE ENTRIES:
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Here is how you could set the CPTs of the "Chest Clinic" example from the manual:
Dim VisitAsia As BNode, Tuberculosis As BNode, Smoking As BNode |
Dim Cancer As BNode, XRay As BNode, TbOrCa As BNode |
Set VisitAsia = net.Node("VisitAsia") |
... |
Set TbOrCa = net.Node("TbOrCa") |
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Dim p(0 To 1) As Single |
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p(0) = 0.01: p(1) = 0.99: VisitAsia.CPTable("") = p |
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p(0) = 0.05: p(1) = 0.95: Tuberculosis.CPTable(Array(0)) = p |
p(0) = 0.01: p(1) = 0.99: Tuberculosis.CPTable(Array(1)) = p |
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p(0) = 0.5: p(1) = 0.5: Smoking.CPTable("") = p |
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p(0) = 0.1: p(1) = 0.9: Cancer.CPTable(Array(0)) = p: |
p(0) = 0.01: p(1) = 0.99: Cancer.CPTable(Array(1)) = p |
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p(0) = 0.98: p(1) = 0.02: XRay.CPTable(Array(0)) = p |
p(0) = 0.05: p(1) = 0.95: XRay.CPTable(Array(1)) = p |
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p(0) = 1: p(1) = 0: TbOrCa.CPTable(Array(0, 0)) = p: |
p(0) = 1: p(1) = 0: TbOrCa.CPTable(Array(0, 1)) = p: |
p(0) = 1: p(1) = 0: TbOrCa.CPTable(Array(1, 0)) = p: |
p(0) = 0: p(1) = 1: TbOrCa.CPTable(Array(1, 1)) = p: |
Here are 6 alternate ways to set the CPT of the TbOrCa node.
Dim p(0 To 1) As Single |
Dim s(0 To 1) As Integer |
s(1) = 0: s(0) = 0: p(0) = 1: p(1) = 0: TbOrCa.CPTable(s) = p: |
s(0) = 1: TbOrCa.CPTable(s) = p: |
s(1) = 1: s(0) = 0: TbOrCa.CPTable(s) = p: |
s(0) = 1: p(0) = 0: p(1) = 1: TbOrCa.CPTable(s) = p: |
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Dim p(0 To 1) As Single |
p(0) = 1: p(1) = 0: TbOrCa.CPTable("present,present") = p: |
p(0) = 1: p(1) = 0: TbOrCa.CPTable("present,absent") = p: |
p(0) = 1: p(1) = 0: TbOrCa.CPTable("absent,present") = p: |
p(0) = 0: p(1) = 1: TbOrCa.CPTable("absent,absent") = p: |
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TbOrCa.StateFuncTable("present,present") = "true": |
TbOrCa.StateFuncTable("present,absent") = "true": |
TbOrCa.StateFuncTable("absent,present") = "true": |
TbOrCa.StateFuncTable("absent,absent") = "false": |
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TbOrCa.CPTable("*,*") = Array(1, 0) |
TbOrCa.CPTable("absent,absent") = Array(0, 1) |
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TbOrCa.StateFuncTable("*,*") = "true" |
TbOrCa.StateFuncTable("absent,absent") = "false" |
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TbOrCa.Equation = "TbOrCa (Tuberculosis, Cancer) = (Tuberculosis || Cancer)" |
TbOrCa.EquationToTable num_samples:=1, samp_unc:=False, add_exist:=False |
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