| static private dradb4 ( int ido, int l1, float cc, float ch, float wa1, int index1, float wa2, int index2, float wa3, int index3 ) : void | ||
| ido | int | |
| l1 | int | |
| cc | float | |
| ch | float | |
| wa1 | float | |
| index1 | int | |
| wa2 | float | |
| index2 | int | |
| wa3 | float | |
| index3 | int | |
| return | void | |
static void dradb4(int ido,int l1,float[] cc,float[] ch,
float[] wa1, int index1,
float[] wa2, int index2,
float[] wa3, int index3)
{
int i,k,t0,t1,t2,t3,t4,t5,t6,t7,t8;
float ci2,ci3,ci4,cr2,cr3,cr4,ti1,ti2,ti3,ti4,tr1,tr2,tr3,tr4;
t0=l1*ido;
t1=0;
t2=ido<<2;
t3=0;
t6=ido<<1;
for(k=0;k<l1;k++)
{
t4=t3+t6;
t5=t1;
tr3=cc[t4-1]+cc[t4-1];
tr4=cc[t4]+cc[t4];
tr1=cc[t3]-cc[(t4+=t6)-1];
tr2=cc[t3]+cc[t4-1];
ch[t5]=tr2+tr3;
ch[t5+=t0]=tr1-tr4;
ch[t5+=t0]=tr2-tr3;
ch[t5+=t0]=tr1+tr4;
t1+=ido;
t3+=t2;
}
if(ido<2)return;
if(ido==2) goto L105;
t1=0;
for(k=0;k<l1;k++)
{
t5=(t4=(t3=(t2=t1<<2)+t6))+t6;
t7=t1;
for(i=2;i<ido;i+=2)
{
t2+=2;
t3+=2;
t4-=2;
t5-=2;
t7+=2;
ti1=cc[t2]+cc[t5];
ti2=cc[t2]-cc[t5];
ti3=cc[t3]-cc[t4];
tr4=cc[t3]+cc[t4];
tr1=cc[t2-1]-cc[t5-1];
tr2=cc[t2-1]+cc[t5-1];
ti4=cc[t3-1]-cc[t4-1];
tr3=cc[t3-1]+cc[t4-1];
ch[t7-1]=tr2+tr3;
cr3=tr2-tr3;
ch[t7]=ti2+ti3;
ci3=ti2-ti3;
cr2=tr1-tr4;
cr4=tr1+tr4;
ci2=ti1+ti4;
ci4=ti1-ti4;
ch[(t8=t7+t0)-1]=wa1[index1+i-2]*cr2-wa1[index1+i-1]*ci2;
ch[t8]=wa1[index1+i-2]*ci2+wa1[index1+i-1]*cr2;
ch[(t8+=t0)-1]=wa2[index2+i-2]*cr3-wa2[index2+i-1]*ci3;
ch[t8]=wa2[index2+i-2]*ci3+wa2[index2+i-1]*cr3;
ch[(t8+=t0)-1]=wa3[index3+i-2]*cr4-wa3[index3+i-1]*ci4;
ch[t8]=wa3[index3+i-2]*ci4+wa3[index3+i-1]*cr4;
}
t1+=ido;
}
if(ido%2 == 1)return;
L105: t1=ido;
t2=ido<<2;
t3=ido-1;
t4=ido+(ido<<1);
for(k=0;k<l1;k++)
{
t5=t3;
ti1=cc[t1]+cc[t4];
ti2=cc[t4]-cc[t1];
tr1=cc[t1-1]-cc[t4-1];
tr2=cc[t1-1]+cc[t4-1];
ch[t5]=tr2+tr2;
ch[t5+=t0]=sqrt2*(tr1-ti1);
ch[t5+=t0]=ti2+ti2;
ch[t5+=t0]=-sqrt2*(tr1+ti1);
t3+=ido;
t1+=t2;
t4+=t2;
}
}