VBScript Deep Learning Introduction - Logistic Regression

question

There are various classifications in life. The following uses test scores as an example. 0 to 59.99 is considered a failure, and the label is 0; 60 to 100 is a pass, and the label is 1. Although we can directly use the if statement to judge and let the computer get the result directly, if we don't tell the computer that >=60 points are considered a pass, but only give it some labeled data, can it let it know by itself? As for the passing score, the answer is yes.

plan

training set x(10000) from 0.00 to 99.99

           y(10000) is 0 or 1, where x(i)>=60 when y(i)=1, otherwise y(i)=0

Logistic regression using the Sigmoid function

The default training times is 500 and the learning rate is 0.1

After the training is over, take an integer from 0 to 99 as the verification set [Actually, this is already included in the training set, it may not be very scientific, it is just an example for everyone to understand the algorithm! 】

the code

Option Explicit

Sub Echo(s)
	Wscript.Echo s
End Sub

Dim xs(10000),ys(10000)
Dim i,j
Dim length:length=10000

For i=0 To length-1
	xs(i)=i/100.0
	ys(i)=0
	If xs(i)>=60 Then
		ys(i)=1.0
	End If
Next

Dim k,b
Randomize

k=Rnd()
b=Rnd()
Echo "k="&k
Echo "b="&b

Function Forward(k,b,x)
	Forward=1.0/(1+Exp(-k*x-b))
End Function

Dim epoch:epoch=500
Dim yh
Dim ls
Dim kp,bp
Dim lr:lr=0.1
Dim c
Dim p

For i=1 To epoch
	Echo "第"&i&"轮训练"
	ls=0
	kp=0
	bp=0
	c=0
	
	For j=0 To length-1
		yh=Forward(k,b,xs(j))
		ls=ls+yh
		bp=bp+yh
		kp=(yh-ys(j))*xs(j)
	Next
	
	ls=-ls/CDbl(length)
	Echo "ls="&ls
	kp=kp/CDbl(length)
	bp=bp/CDbl(length)
	k=k-lr*kp
	b=b-lr*bp
	
	For j=0 To length-1
		yh=Forward(k,b,xs(j))
		If yh<0.5 and ys(j)<0.5 or yh>=0.5 and ys(j)>=0.5 Then
			c=c+1
		End If
	Next
	
	p=c*100/CDbl(length)
	Echo "训练集拟合度："&Round(p,2)&"%"
	Echo ""
	If p>99.99999999 Then
		Exit For
	End If
Next

Echo "k="&k
Echo "b="&b

c=0
Dim tx
For i=0 To 99
	yh=Forward(k,b,i*1.0)
	If i<60 and yh<0.5 or i>=60 and yh>=0.5 Then
		c=c+1
	End If
Next
p=c*1.0
Echo "测试集拟合度："&Round(p,2)&"%"

result