正弦函数的绘制的一种方法。（坐标变换与放大）

Private Sub Button1_Click( ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim G As Graphics

G = PictureBox1.CreateGraphics()

' 移动坐标原点 ( 那么原点下就变成了 (20,pictruebox1.height\2))

G.TranslateTransform(20, PictureBox1.Height \ 2)

' 绘制 X 轴与 Y 轴

'Y 轴

G.DrawLine(Pens.Black, 20, -PictureBox1.Height \ 2, 20, PictureBox1.Height \ 2)

'X 轴

G.DrawLine(Pens.Black, -20, 0, PictureBox1.Width, 0)

' 正弦函数

Dim X, Y As Double

For X = 0 To 400 Step 0.002

Y = 60 * Math.Sin(2 * 3.1415926 * X / 200)

G.DrawLine(Pens.Blue, CInt (X), 0, CInt (X), CInt (Y))

Application.DoEvents()

For X = 0 To 400 Step 0.002

Y = 60 * Math.Sin(2 * 3.1415926 * X / 200)

G.DrawLine(Pens.Red, CInt (X), 0, CInt (X), CInt (Y))

Application.DoEvents()

End Sub