将不正确的值写入文本文件

Question

我想将正弦函数的值写入文本文件。功能是

在我的图形计算器中，如果我想以弧度绘制函数，我还必须添加 π。

我要如何在源代码中写这个？每次都出现错误值，无论我插入或省略 π。

我希望 t = 0 到 14400 以及从 t = 69060 开始的 y 值为 0。在这两者之间，根据它的公式，y = 0 的正弦函数应该上升，达到 8，然后再次下降（如 69060 所说的第二个零）。

Private Sub ButtonStart_Click(sender As Object, e As EventArgs) Handles ButtonStart.Click
        Dim Path As String = ""
        Using SFD As New CommonSaveFileDialog
            SFD.Title = "Ordner, in dem die Textdatei gespeichert werden soll, auswählen"
            SFD.Filters.Add(New CommonFileDialogFilter("Textdateien", ".txt"))
            Dim di As New IO.DirectoryInfo(Application.StartupPath)
            If di.Parent.Name = "bin" Then
                di = di.Parent.Parent.Parent                              ' AnyCPU
            ElseIf di.Parent.Parent.Name = "bin" Then
                di = di.Parent.Parent.Parent.Parent                       ' x64, x86
            End If
            If System.IO.Directory.Exists(di.FullName) Then
                SFD.InitialDirectory = di.FullName
            Else
                SFD.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
            End If
            If SFD.ShowDialog() = CommonFileDialogResult.Ok Then
                Path = SFD.FileName & ".txt"
            Else
                Return
            End If
        End Using

        ButtonStart.BackColor = Color.FromArgb(255, 255, 0)
        Application.DoEvents()

        Using textfile As System.IO.StreamWriter = My.Computer.FileSystem.OpenTextFileWriter(Path, False, System.Text.Encoding.UTF8)
            textfile.WriteLine($"Time{Tab}V(OUT)")
            For t As UInt32 = 0UI To 86400UI Step 1UI
                If t < 14400UI OrElse (t >= 14400UI AndAlso t <= 69060UI) Then
                    textfile.WriteLine(t.ToString(Eng).PadLeft(10, "0"c) & Tab & 0.0.ToString(Eng))
                Else
                    Dim Value As Double = 8.0 * Math.Sin(1.0 * Math.PI / 54660.0 * t + 2.0 * Math.PI - 0.2634467618)
                    textfile.WriteLine(t.ToString(Eng).PadLeft(10, "0"c) & Tab & Value.ToString(Eng))
                End If
            Next
            textfile.Close()
        End Using

        ButtonStart.BackColor = Color.FromArgb(0, 255, 0)
    End Sub

Answer 1

我找到了解决办法。它一定要是 振幅 * sin(2πf*t + rad 相位) + offset

Using textfile As System.IO.StreamWriter = My.Computer.FileSystem.OpenTextFileWriter(Path, False, System.Text.Encoding.UTF8)

            For t As UInt32 = 0UI To 86400UI Step 1UI
                If t < 14400UI OrElse (t > 69060UI AndAlso t <= 86400UI) Then
                    textfile.WriteLine(t.ToString(Eng).PadLeft(10, "0"c) & Tab & 0.0.ToString(Eng))
                Else
                    Dim Value As Double = 4.0 * Math.Sin(2 * Math.PI * 1.0 / 54660.0 * t + 177.0 * Math.PI / 180.0) + 4.0
                    textfile.WriteLine(t.ToString(Eng).PadLeft(10, "0"c) & Tab & Value.ToString(Eng))
                End If
            Next
            textfile.Close()
        End Using

Answer 2

这应该是你的功能

Function f(t As Double) As Double
    Dim amplitude = 8
    Dim period = 54660
    Dim phaseDegrees = 177
    Dim phaseRadians = phaseDegrees * Math.PI / 180
    Dim vertical = 0
    Dim a = amplitude
    Dim b = 2 * Math.PI / period
    Dim c = phaseRadians
    Dim d = vertical
    Return a * Math.Sin(b * (t + c)) + d
End Function

查看图片，来自https://www.mathsisfun.com/algebra/amplitude-period-frequency-phase-shift.html

将不正确的值写入文本文件

Incorrect values are written to the text file

vb.net

math

plot

trigonometry

radians