{ /* for(1) */ b=1; i=L-1; while ( i>0 ) { b=b*2; i--; } /* b= 2^(L-1) */ for ( j=0;j<=b-1;j++ ) /* for (2) */ { p=1; i=7-L; while ( i>0 ) /* p=pow(2,7-L)*j; */ { p=p*2; i--; } p=p*j; for ( k=j;k<8;k=k+2*b ) /* for (3) */ { TR=dataR[k]; TI=dataI[k]; temp=dataR[k+b]; dataR[k]=dataR[k]+dataR[k+b]*cos_tab[p]+dataI[k+b]*sin_tab[p]; dataI[k]=dataI[k]-dataR[k+b]*sin_tab[p]+dataI[k+b]*cos_tab[p]; dataR[k+b]=TR-dataR[k+b]*cos_tab[p]-dataI[k+b]*sin_tab[p]; dataI[k+b]=TI+temp*sin_tab[p]-dataI[k+b]*cos_tab[p]; } /* END for (3) */ } /* END for (2) */ } /* END for (1) */ for ( i=0;i<8/2;i++ ) { w[i]=sqrt(dataR[i]*dataR[i]+dataI[i]*dataI[i]); }
(3)变换结果
Value[8]={0,199.99,400,452.74,0,335.93,565.69,432.42};
