1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
subroutine passb4 (ido,l1,cc,ch,wa1,wa2,wa3)
implicit double precision (a-h,o-z)
dimension cc(ido,4,l1) ,ch(ido,l1,4) ,
1 wa1(1) ,wa2(1) ,wa3(1)
if (ido .ne. 2) go to 102
do 101 k=1,l1
ti1 = cc(2,1,k)-cc(2,3,k)
ti2 = cc(2,1,k)+cc(2,3,k)
tr4 = cc(2,4,k)-cc(2,2,k)
ti3 = cc(2,2,k)+cc(2,4,k)
tr1 = cc(1,1,k)-cc(1,3,k)
tr2 = cc(1,1,k)+cc(1,3,k)
ti4 = cc(1,2,k)-cc(1,4,k)
tr3 = cc(1,2,k)+cc(1,4,k)
ch(1,k,1) = tr2+tr3
ch(1,k,3) = tr2-tr3
ch(2,k,1) = ti2+ti3
ch(2,k,3) = ti2-ti3
ch(1,k,2) = tr1+tr4
ch(1,k,4) = tr1-tr4
ch(2,k,2) = ti1+ti4
ch(2,k,4) = ti1-ti4
101 continue
return
102 do 104 k=1,l1
do 103 i=2,ido,2
ti1 = cc(i,1,k)-cc(i,3,k)
ti2 = cc(i,1,k)+cc(i,3,k)
ti3 = cc(i,2,k)+cc(i,4,k)
tr4 = cc(i,4,k)-cc(i,2,k)
tr1 = cc(i-1,1,k)-cc(i-1,3,k)
tr2 = cc(i-1,1,k)+cc(i-1,3,k)
ti4 = cc(i-1,2,k)-cc(i-1,4,k)
tr3 = cc(i-1,2,k)+cc(i-1,4,k)
ch(i-1,k,1) = tr2+tr3
cr3 = tr2-tr3
ch(i,k,1) = ti2+ti3
ci3 = ti2-ti3
cr2 = tr1+tr4
cr4 = tr1-tr4
ci2 = ti1+ti4
ci4 = ti1-ti4
ch(i-1,k,2) = wa1(i-1)*cr2-wa1(i)*ci2
ch(i,k,2) = wa1(i-1)*ci2+wa1(i)*cr2
ch(i-1,k,3) = wa2(i-1)*cr3-wa2(i)*ci3
ch(i,k,3) = wa2(i-1)*ci3+wa2(i)*cr3
ch(i-1,k,4) = wa3(i-1)*cr4-wa3(i)*ci4
ch(i,k,4) = wa3(i-1)*ci4+wa3(i)*cr4
103 continue
104 continue
return
end
|
