//
//?The?Computer?Image
//
//?This?file?implements?a?Fast?Fourier?Transform?of?a?1D?function
//

#include?
#include?“../fft.h“

#define?SWAP（ab）?tempr=（a）;（a）=（b）;（b）=tempr

void?four1（float?*dataint?nnint?isign）
//
//?Replaces?data?by?its?discrete?Fourier?transform?if?isign?is?input?as?1;
//?or?replaces?data?by?nn?times?its?inverse?discrete?Fourier?transform?if
//?isign?is?input?as?-1.?data?is?a?complex?array?of?length?nn?input?as?a?
//?real?array?data[1..2*nn].?nn?must?be?an?integer?power?of?2.
//
{
?????int?nmmaxmjistepi;
?????double?wtempwrwprwpiwitheta;
?????float?temprtempi;

?????n=nn<<1;
?????j=1;
?????for（?i=1;i??????????{
???????????if?（j>i）
??????????????{
???????????????SWAP（data[j]data[i]）;
???????????????SWAP（data[j+1]data[i+1]）;
??????????????}
???????????m=n>>1;
???????????while（?m>=2?&&?j>m?）
??????????????????{
???????????????????j-=m;
???????????????????m>>=1;
??????????????????}
???????????j+=m;
??????????}
?????mmax=2;
?????while（?n>mmax?）
????????????{
?????????????istep=mmax<<1;
?????????????theta=6.28318530717959/（isign*mmax）;
?????????????wtemp=sin（0.5*theta）;
?????????????wpr=-2.0*wtemp*wtemp;
?????????????wpi=sin（theta）;
?????????????wr=1.0;
?????????????wi=0.0;
?????????????for（?m=1;m?????????????????{
??????????????????for（?i=m;i<=n;i+=istep?）
???????????????????????{
????????????????????????j=i+mmax;
????????????????????????tempr=wr*data[j]-wi*data[j+1];
????????????????????????tempi=wr*data[j+1]+wi*data[j];
????????????????????????data[j]=data[i]-tempr;
????????????????????????data[j+1]=data[i+1]-tempi;
????????????????????????data[i]+=tempr;
????????????????????????data[i+1]+=tempi;
???????????????????????}
??????????????????wr=（wtemp=wr）*wpr-wi*wpi+wr;
??????????????????wi=wi*wpr+wtemp*wpi+wi;
?????????????????}
?????????????mmax=istep;
????????????}

}

void?twofft（float?*data1float?*data2float?*fft1float?*fft2int?n）
//
//?Given?two?real?input?arrays?data[1..n]?and?data2[1..n]?this?routine
//?calls?four1?and?returns?two?complex?output?arrays?fft1?and?fft2
//?each?of?complex?length?n?（real?dimensions?of?[1..2n]）?which?contain
//?the?discrete?Fourier?transforms?of?the?respective?datas.?n?must?be?
//?a?integer?power?of?two.
//
{
?????int?nn3nn2jjj;
?????float?repremaipaim;

?????nn3=1+（nn2=2+n+n）;
?????for（?j=1jj=2;j<=n;j++jj+=2?）
??????????{
???????????fft1[jj-1]=data1[j];
???????????fft1[jj]=data2[j];
??????????}
?????four1（fft1n1）;
?????fft2[1]=fft1[2];
?????fft1[2]=fft2[2]=0.0;
?????for（?j=3;j<=n+1;j+=2?）
??????????{
???????????rep=0.5*（fft1[j]+fft1[nn2-j]）;
???????????rem=0.5*（fft1[j]-fft1[nn2-j]）;
???????????aip=0.5*（fft1[j+1]+fft1[nn3-j]）;
???????????aim=0.5*（fft1[j+1]-fft1[nn3-j]）;
???????????fft1[j]=rep;
???????????fft1[j+1]=aim;
???????????fft1[nn2-j]=rep;
???????????fft1[nn3-j]=-aim;
???????????fft2[j]=aip;
???????????fft2[j+1]=-rem;
??

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件?????352256??2002-10-01?04:47??Fly3D2.0\autorun.exe

?????文件???????2998??1999-09-22?15:41??Fly3D2.0\autorun.ico

?????文件?????????47??1999-09-23?04:21??Fly3D2.0\autorun.inf

?????文件?????????49??2000-08-28?19:13??Fly3D2.0\Fly3D.url

?????文件??????24064??2002-09-17?23:34??Fly3D2.0\readme.doc

?????文件??????36864??2002-03-13?23:13??Fly3D2.0\sse_code.doc

?????文件??????10130??1994-05-09?00:23??Fly3D2.0\wfft1d\EQANLIZE.CPP

?????文件??????13843??2002-09-16?22:48??Fly3D2.0\wfft1d\WFFT1D.CPP

?????文件????????221??1997-12-23?20:12??Fly3D2.0\wfft1d\WFFT1D.DEF

?????文件??????89600??1998-01-08?21:43??Fly3D2.0\wfft1d\WFFT1D.EXE

?????文件??????26346??1998-01-08?21:43??Fly3D2.0\wfft1d\WFFT1D.IDE

?????文件?????????77??1995-10-12?00:25??Fly3D2.0\wfft1d\WFFT1D.INI

?????文件???????5996??1998-01-08?21:42??Fly3D2.0\wfft1d\WFFT1D.RC

?????文件??????10101??1998-01-05?19:16??Fly3D2.0\wfft1d\fft.cpp

?????文件????????279??1994-05-05?23:00??Fly3D2.0\wfft1d\fft.h

?????文件??????59688??1997-12-18?21:03??Fly3D2.0\wfft1d\fpobtn.dll

?????文件???26344204??2002-10-04?03:00??Fly3D2.0\setup\Fly3D2_full.exe

-----------?---------??----------?-----??----

?????????????26976763??卷?1???????????????17