関数と導関数
2016/10/06

いつの間にか参考書変わってます(^^;)。
花火を打ち上げたときの運動だそうです。横軸は時間、縦軸は高さ。
オレンジ色の破線は導関数。
刻みが細かすぎてグラフ用紙がつぶれるので背景はコメントアウト。
'打ち上げ花火
Private Sub btnHanabi_Click(sender As Object, e As EventArgs) Handles btnHanabi.Click
Dim minX As Integer = 0
Dim maxX As Integer = 5
Dim minY As Integer = -30
Dim maxY As Integer = 20
'setGrid(minX, maxX, minY, maxY)
Chart1.Series.Clear()
Chart1.Series.Add("ax")
Chart1.Series("ax").ChartType = SeriesChartType.FastPoint
Chart1.Series.Add("ax2")
Chart1.Series("ax2").ChartType = SeriesChartType.FastPoint
Dim y As Double
Dim y2 As Double '導関数用
Dim x As Double = minX
Dim s As Double = 0.1
Dim icount As Integer
icount = (maxX - minX) * (1 / s)
For index = 1 To icount Step s
y = 20 * x - 5 * x * x ' y = 20x - 5x^2
y2 = 20 - 10 * x ' y' = 20 -10x
If y > maxY Then
ElseIf y < minY Then
Else
Chart1.Series("ax").Points.AddXY(x, y)
Chart1.Series("ax2").Points.AddXY(x, y2)
End If
x = x + s
Next
End Sub