00001 subroutine passb3 (ido,l1,cc,ch,wa1,wa2)
00002 dimension cc(ido,3,l1) ,ch(ido,l1,3) ,
00003 1 wa1(1) ,wa2(1)
00004 data taur,taui /-.5,.866025403784439/
00005 if (ido .ne. 2) go to 102
00006 do 101 k=1,l1
00007 tr2 = cc(1,2,k)+cc(1,3,k)
00008 cr2 = cc(1,1,k)+taur*tr2
00009 ch(1,k,1) = cc(1,1,k)+tr2
00010 ti2 = cc(2,2,k)+cc(2,3,k)
00011 ci2 = cc(2,1,k)+taur*ti2
00012 ch(2,k,1) = cc(2,1,k)+ti2
00013 cr3 = taui*(cc(1,2,k)-cc(1,3,k))
00014 ci3 = taui*(cc(2,2,k)-cc(2,3,k))
00015 ch(1,k,2) = cr2-ci3
00016 ch(1,k,3) = cr2+ci3
00017 ch(2,k,2) = ci2+cr3
00018 ch(2,k,3) = ci2-cr3
00019 101 continue
00020 return
00021 102 do 104 k=1,l1
00022 do 103 i=2,ido,2
00023 tr2 = cc(i-1,2,k)+cc(i-1,3,k)
00024 cr2 = cc(i-1,1,k)+taur*tr2
00025 ch(i-1,k,1) = cc(i-1,1,k)+tr2
00026 ti2 = cc(i,2,k)+cc(i,3,k)
00027 ci2 = cc(i,1,k)+taur*ti2
00028 ch(i,k,1) = cc(i,1,k)+ti2
00029 cr3 = taui*(cc(i-1,2,k)-cc(i-1,3,k))
00030 ci3 = taui*(cc(i,2,k)-cc(i,3,k))
00031 dr2 = cr2-ci3
00032 dr3 = cr2+ci3
00033 di2 = ci2+cr3
00034 di3 = ci2-cr3
00035 ch(i,k,2) = wa1(i-1)*di2+wa1(i)*dr2
00036 ch(i-1,k,2) = wa1(i-1)*dr2-wa1(i)*di2
00037 ch(i,k,3) = wa2(i-1)*di3+wa2(i)*dr3
00038 ch(i-1,k,3) = wa2(i-1)*dr3-wa2(i)*di3
00039 103 continue
00040 104 continue
00041 return
00042 end
1.7.1
