数学函数作图器.txt

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数学函数作图器
 

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第八军团 时间：2003-12-29 12:39:43 
   
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() '画正弦曲线 
'用For循环绘点，使其按正弦规律变化。 
'步长小，使曲线比较平滑，还能形成动画效果 
For a = -2 * Pi To 2 * Pi Step Pi / 6000 
Dot = DrawDot(a, Sin(a) * 5, RGB(0, 255, 0)) 
Next a 
wor = PrintWord(3, -6, "正弦曲线 y=Sinx") 
End Sub 
Private Sub Command2_Click() 
For a = -2 * Pi To 2 * Pi Step Pi / 6000 
Dot = DrawDot(a, Cos(a) * 5, RGB(255, 0, 0)) 
Next a 
wor = PrintWord(4, 6, "余弦曲线 y=Cosx") 
End Sub 
Private Sub Command3_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 Command4_Click() 
For a = -8 To 8 Step Pi / 6000 
If a = 0 Then GoTo err0 '除数不能为0 
Dot = DrawDot(a, 1 / a, RGB(255, 0, 255)) 
err0: 
Next a 
wor = PrintWord(6, 2, "双曲线 y=1/x") 
End Sub 
Private Sub Command5_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 
Picture1.BackColor = vbWhite 
Command1.Caption = "正弦曲线" 
Command2.Caption = "余弦曲线" 
Command3.Caption = "二次曲线" 
Command4.Caption = "双曲线" 
Command5.Caption = "清空" 
XY 
End Sub 

Private Sub form_Resize() 
Picture1.Width = Me.Width * 0.94 
End Sub