frmfft.frm

我自己编写的VB的FFT程序

VERSION 5.00
Begin VB.Form frmFFT 
   AutoRedraw      =   -1  'True
   Caption         =   "FFT"
   ClientHeight    =   9315
   ClientLeft      =   60
   ClientTop       =   435
   ClientWidth     =   9375
   LinkTopic       =   "Form1"
   ScaleHeight     =   9315
   ScaleWidth      =   9375
   StartUpPosition =   3  'Windows Default
   Begin VB.PictureBox picIFFT 
      AutoRedraw      =   -1  'True
      Height          =   2175
      Left            =   120
      ScaleHeight     =   2115
      ScaleWidth      =   9075
      TabIndex        =   6
      Top             =   7080
      Width           =   9135
   End
   Begin VB.CommandButton Command3 
      Caption         =   "Command3"
      Height          =   495
      Left            =   4320
      TabIndex        =   5
      Top             =   120
      Width           =   1215
   End
   Begin VB.PictureBox picFreDomain 
      AutoRedraw      =   -1  'True
      Height          =   2295
      Left            =   120
      ScaleHeight     =   2235
      ScaleWidth      =   9075
      TabIndex        =   4
      Top             =   4560
      Width           =   9135
   End
   Begin VB.PictureBox picTimeDomain 
      AutoRedraw      =   -1  'True
      Height          =   3375
      Left            =   120
      ScaleHeight     =   3315
      ScaleWidth      =   9075
      TabIndex        =   3
      Top             =   1080
      Width           =   9135
   End
   Begin VB.CommandButton Command2 
      Caption         =   "FFT"
      Height          =   495
      Left            =   2280
      TabIndex        =   2
      Top             =   120
      Width           =   1815
   End
   Begin VB.TextBox Text1 
      Height          =   495
      Left            =   5640
      TabIndex        =   1
      Text            =   "Text1"
      Top             =   120
      Width           =   3015
   End
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   495
      Left            =   240
      TabIndex        =   0
      Top             =   120
      Width           =   1695
   End
End
Attribute VB_Name = "frmFFT"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit

Private Sub Command1_Click()
Dim MyFile As String
Dim str As String
Dim sFile As String
str = "Pn1_#4_16k.wav"
sFile = App.Path & "\OkFile\" & str
MyFile = Dir(sFile)
If Dir(sFile) <> str Then
    Text1.Text = MyFile
Else
    Text1.Text = 1
End If

End Sub

Private Sub Command2_Click()
Call Test
Call Show_Pic
End Sub

Private Sub Command3_Click()
    Dim i As Integer
    Dim Y() As Double
    Dim LenDataNov As Long
    Dim Freq As Long
    Freq = 8000
    LenDataNov = 1024
    ReDim Y(1 To LenDataNov) As Double
    For i = 0 To 1023
        Y(i + 1) = 5 * Sin(2 * PI * i / 128) + 4 * Sin(2 * PI * i / 64) + 2 * Sin(2 * PI * i / 32)
    Next
    PlotFreq.FFTWave Y(), LenDataNov, Freq, "5 Seconds"
End Sub

Private Sub Form_Load()
    Dim i As Integer
    picTimeDomain.Scale (-50, 10)-(1050, -10)
    picTimeDomain.Line (-50, 0)-(1050, 0)
    picTimeDomain.Line (0, -10)-(0, 10)
    For i = 1 To 16
        picTimeDomain.Line (64 * i, 0.5)-(64 * i, 0)
        picTimeDomain.PSet (64 * i, -0.5)
        picTimeDomain.Print CStr(i)
    Next
    
    picFreDomain.Scale (-10, 10)-(100, 0)
    
    picIFFT.Scale (-50, 10)-(1050, -10)
    picIFFT.Line (-50, 0)-(1050, 0)
    picIFFT.Line (0, -10)-(0, 10)
    For i = 1 To 16
        picIFFT.Line (64 * i, 0.5)-(64 * i, 0)
        picIFFT.PSet (64 * i, -0.5)
        picIFFT.Print CStr(i)
    Next
End Sub
Private Sub Show_Pic()
    Dim i As Integer
    
    picTimeDomain.CurrentX = 0
    picTimeDomain.CurrentY = 0
    
    For i = 1 To 1023
        picTimeDomain.Line (i - 1, TD(i - 1).re)-(i, TD(i).re)
    Next
    
    For i = 0 To 511
        picFreDomain.Line (i, Sqr(FD(i).re * FD(i).re + FD(i).im * FD(i).im) / 500)-(i, 0)
    Next
    
    picIFFT.CurrentX = 0
    picIFFT.CurrentY = X1(0).re
    For i = 1 To 1023
        picIFFT.Line (i - 1, X1(i - 1).re)-(i, X1(i).re)
    Next
End Sub

Private Sub picFreDomain_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
    Dim sX As Integer
    Dim sY As Integer
    sX = X
    sY = Y
    Text1.Text = "x = " & CStr(sX) & ",y = " & CStr(sY) & ",freq = " & CStr(sX * Fs)
End Sub