求画函数图

'贴入下面的代码,即可：
'--------------------------------------
Const Pi = 3.1415926535 '定义圆周率
Dim a,wor
'定义用于在Picture1上的一个位置打印字符函数
Private Function PrintWord(X,Y,Word As String)
With Picture1
.CurrentX = X
.CurrentY = Y
.ForeColor = RGB(0,0,255)
End With
Picture1.Print Word
End Function
'定义画点函数
Private Function DrawDot(Px,Py,Color)
Picture1.PSet (Px,Py),Color
End Function
Sub XY() '建立直角坐标系
Picture1.DrawWidth = 1 '设置线条宽度
Picture1.Cls
'设定用户坐标系,坐标原点在Picture1中心
Picture1.Scale (-10,10)-(10,-10)
Picture1.Line (-10,0)-(10,0),RGB(0,0,255)
Picture1.Line -(9.5,0.5),RGB(0,0,255)
Picture1.Line (10,0)-(9.5,-0.5),RGB(0,0,255)
Picture1.ForeColor = RGB(0,0,255)
Picture1.Print "X"
'画 X 轴
Picture1.Line (0,-10)-(0,10),RGB(0,0,255)
Picture1.Line -(0.5,9.5),RGB(0,0,255)
Picture1.Line (0,10)-(-0.5,9.5),RGB(0,0,255)
Picture1.Print "Y"
'画 Y 轴
For lin = -9 To 9
Picture1.Line (lin,0)-(lin,0.25)
wor = PrintWord(lin - 0.5,-0.5,Str(lin))
Picture1.Line (0,lin)-(-0.25,lin)
If lin <> 0 Then
wor = PrintWord(-0.9,lin,Str(lin))
End If
Next lin
Picture1.DrawWidth = 2
End Sub
Private Sub Command1_Click()
For a = -3 To 3 Step Pi / 6000
Dot = DrawDot(a,a ^ 2,RGB(0,0,0))
Next a
wor = PrintWord(4,9,"二次曲线 y=x^2")
End Sub
Private Sub Command2_Click() '清空屏幕
XY
End Sub
Private Sub Form_Load()
Me.Caption = "数学函数作图?quot;"
Me.Show
Me.AutoRedraw = True
Command1.Caption = "二次曲线"
Command2.Caption = "清空"
XY
End Sub
Private Sub Form_Resize()
Picture1.Width = Me.Width * 0.94
Picture1.Height = Me.Height - (Command1.Height * 3 + 100)
Command1.Top = Me.Height - (Command1.Height * 2 + 100)
Command2.Top = Me.Height - (Command1.Height * 2 + 100)
Command1.Left = Me.Width * 0.01
Command2.Left = Me.Width * 0.21
XY
End Sub