00001 subroutine zpassb4 (ido,l1,cc,ch,wa1,wa2,wa3)
00002 implicit double precision (a-h,o-z)
00003 dimension cc(ido,4,l1) ,ch(ido,l1,4) ,
00004 1 wa1(1) ,wa2(1) ,wa3(1)
00005 if (ido .ne. 2) go to 102
00006 do 101 k=1,l1
00007 ti1 = cc(2,1,k)-cc(2,3,k)
00008 ti2 = cc(2,1,k)+cc(2,3,k)
00009 tr4 = cc(2,4,k)-cc(2,2,k)
00010 ti3 = cc(2,2,k)+cc(2,4,k)
00011 tr1 = cc(1,1,k)-cc(1,3,k)
00012 tr2 = cc(1,1,k)+cc(1,3,k)
00013 ti4 = cc(1,2,k)-cc(1,4,k)
00014 tr3 = cc(1,2,k)+cc(1,4,k)
00015 ch(1,k,1) = tr2+tr3
00016 ch(1,k,3) = tr2-tr3
00017 ch(2,k,1) = ti2+ti3
00018 ch(2,k,3) = ti2-ti3
00019 ch(1,k,2) = tr1+tr4
00020 ch(1,k,4) = tr1-tr4
00021 ch(2,k,2) = ti1+ti4
00022 ch(2,k,4) = ti1-ti4
00023 101 continue
00024 return
00025 102 do 104 k=1,l1
00026 do 103 i=2,ido,2
00027 ti1 = cc(i,1,k)-cc(i,3,k)
00028 ti2 = cc(i,1,k)+cc(i,3,k)
00029 ti3 = cc(i,2,k)+cc(i,4,k)
00030 tr4 = cc(i,4,k)-cc(i,2,k)
00031 tr1 = cc(i-1,1,k)-cc(i-1,3,k)
00032 tr2 = cc(i-1,1,k)+cc(i-1,3,k)
00033 ti4 = cc(i-1,2,k)-cc(i-1,4,k)
00034 tr3 = cc(i-1,2,k)+cc(i-1,4,k)
00035 ch(i-1,k,1) = tr2+tr3
00036 cr3 = tr2-tr3
00037 ch(i,k,1) = ti2+ti3
00038 ci3 = ti2-ti3
00039 cr2 = tr1+tr4
00040 cr4 = tr1-tr4
00041 ci2 = ti1+ti4
00042 ci4 = ti1-ti4
00043 ch(i-1,k,2) = wa1(i-1)*cr2-wa1(i)*ci2
00044 ch(i,k,2) = wa1(i-1)*ci2+wa1(i)*cr2
00045 ch(i-1,k,3) = wa2(i-1)*cr3-wa2(i)*ci3
00046 ch(i,k,3) = wa2(i-1)*ci3+wa2(i)*cr3
00047 ch(i-1,k,4) = wa3(i-1)*cr4-wa3(i)*ci4
00048 ch(i,k,4) = wa3(i-1)*ci4+wa3(i)*cr4
00049 103 continue
00050 104 continue
00051 return
00052 end
1.7.1
