Imports BasicDSP
Public Class dsp2ex1

    ' global signal
    Dim wv As New Signal

    Public Sub DisplayGraph(ByVal filename As String)
        ' get first 1024 samples
        Dim cwv As ComplexWaveform = wv.Cut(1, 1024).Float.Complex

        ' window
        cwv = Window.Hamming(cwv)

        ' calculate spectrum
        Dim s As Spectrum = DFT.ComplexFFT(cwv)

        ' plot everything
        Dim gr As New Graph(Me.CreateGraphics, zgc, 2, 1)
        gr.PlotComplexWaveform(1, cwv, "Windowed " & filename)
        gr.PlotDbSpectrum(2, s.Half, "Log Magnitude Spectrum")
        zgc.Refresh()
    End Sub

    Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click
        If OpenFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
            If (wv.LoadWaveFile(OpenFileDialog1.FileName)) Then
                DisplayGraph(OpenFileDialog1.FileName)
            End If
        End If
    End Sub
End Class