?? fftdll.htm
字號:
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<meta name="Author" content="Lingsong He">
<meta name="GENERATOR" content="Mozilla/4.5 [en] (Win98; I) [Netscape]">
<meta name="Description" content="Sound card data acquiration api. 32bit dll, free to use">
<meta name="KeyWords" content="sound card, daq, A/D, data acquiration, D/A, dll, free">
<title>FFT DLL</title>
</head>
<body text="#000000" bgcolor="#FFFFFF" link="#0000EE" vlink="#551A8B" alink="#FF0000">
<b><font face="Times New Roman,Times"><font color="#FF0000"><font size=-1><a href="http://drhe.tripod.com" target="_top">美國站首頁</a><a href="http://drhe.topcool.net" target="_top">北京站首頁</a></font></font></font></b>
<center><table BORDER=0 COLS=1 WIDTH="90%" HEIGHT="100" >
<tr>
<td>
<center><b><font face="Times New Roman,Times"><font color="#CC0000"><font size=+2>FFT
DLL</font></font></font></b>
<hr ALIGN=LEFT WIDTH="100%"></center>
<font face="Times New Roman,Times">FFT DLL 是我們設計的一個免費的 32 動態鏈接庫,它提供了最基本的Fourier變換功能,配合本站提供的</font>
<br><font face="Times New Roman,Times">Sound Daq, Jpeg Api動態鏈接庫,你可以很容易設計一個簡單的基于聲卡的譜分析程序。</font>
<br><font face="Times New Roman,Times"><font color="#000000">Press here
to <a href="fft.zip">download</a>.</font></font>
<br>
<hr WIDTH="100%">
<br><b><font face="Times New Roman,Times"><font color="#CC0000">FFT DLL
package include four file:</font></font></b>
<br><b><font face="Times New Roman,Times"><font color="#3333FF">1.fftdll.h</font></font></b>
<br><b><font face="Times New Roman,Times"><font color="#3333FF">2.fftdll.lib</font></font></b>
<br><b><font face="Times New Roman,Times"><font color="#3333FF">3.fftdll.dll</font></font></b>
<br><b><font face="Times New Roman,Times"><font color="#3333FF">4.fftdll.htm
(Help file)</font></font></b>
<br><b><font face="Times New Roman,Times"><font color="#3333FF">5.testfft.zip
(VC++ Example program)</font></font></b>
<br><font face="Times New Roman,Times"><font color="#CC0000">.</font></font>
<br><b><font face="Times New Roman,Times"><font color="#CC0000">Functions
in FFT DLL:</font></font></b>
<br><b><font face="Times New Roman,Times"><font color="#3333FF">1. void
fft(short sw,short n,float *x,float *y)</font></font></b>
<br><font face="Times New Roman,Times"><font color="#000000">sw=0 FFT ,
sw=1 IFFT</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">n=256/512/1024/2048/4096</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">x: Array of
data</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">y: Array of
data</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">.</font></font>
<br><b><font face="Times New Roman,Times"><font color="#3333FF">2.void
spectrum_r_i(float *wave,float *re,float *im)</font></font></b>
<br><font face="Times New Roman,Times"><font color="#000000">wave: raw
data of signal, 1024 sample point</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">re: real part
of spectrum</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">im:imaginary
part of sprectrum</font></font>
<p><b><font face="Times New Roman,Times"><font color="#3333FF">3.void spectrum_a_p(float
*wave,float *a,float *p)</font></font></b>
<br><font face="Times New Roman,Times"><font color="#000000">wave: raw
data of signal, 1024 sample point</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">a: amplitude
of spectrum</font></font>
<br><font face="Times New Roman,Times"><font color="#000000">p: phase of
sprectrum</font></font>
<br> </td>
</tr>
</table></center>
<blockquote>
<center><table BORDER=0 COLS=1 WIDTH="90%" HEIGHT="100" >
<tr>
<td><b><font color="#990000">Example of VC++:</font></b>
<br><img SRC="fft.gif" height=351 width=549>
<br>
<hr WIDTH="100%">
<center>1999.12.20</center>
</td>
</tr>
</table></center>
</blockquote>
</body>
</html>
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -