SUBROUTINE RFFTB1 (N,C,CH,WA,IFAC) DIMENSION CH(1) ,C(1) ,WA(1) ,IFAC(1) NF = IFAC(2) NA = 0 L1 = 1 IW = 1 DO 116 K1=1,NF IP = IFAC(K1+2) L2 = IP*L1 IDO = N/L2 IDL1 = IDO*L1 IF (IP .NE. 4) GO TO 103 IX2 = IW+IDO IX3 = IX2+IDO IF (NA .NE. 0) GO TO 101 CALL RADB4 (IDO,L1,C,CH,WA(IW),WA(IX2),WA(IX3)) GO TO 102 101 CALL RADB4 (IDO,L1,CH,C,WA(IW),WA(IX2),WA(IX3)) 102 NA = 1-NA GO TO 115 103 IF (IP .NE. 2) GO TO 106 IF (NA .NE. 0) GO TO 104 CALL RADB2 (IDO,L1,C,CH,WA(IW)) GO TO 105 104 CALL RADB2 (IDO,L1,CH,C,WA(IW)) 105 NA = 1-NA GO TO 115 106 IF (IP .NE. 3) GO TO 109 IX2 = IW+IDO IF (NA .NE. 0) GO TO 107 CALL RADB3 (IDO,L1,C,CH,WA(IW),WA(IX2)) GO TO 108 107 CALL RADB3 (IDO,L1,CH,C,WA(IW),WA(IX2)) 108 NA = 1-NA GO TO 115 109 IF (IP .NE. 5) GO TO 112 IX2 = IW+IDO IX3 = IX2+IDO IX4 = IX3+IDO IF (NA .NE. 0) GO TO 110 CALL RADB5 (IDO,L1,C,CH,WA(IW),WA(IX2),WA(IX3),WA(IX4)) GO TO 111 110 CALL RADB5 (IDO,L1,CH,C,WA(IW),WA(IX2),WA(IX3),WA(IX4)) 111 NA = 1-NA GO TO 115 112 IF (NA .NE. 0) GO TO 113 CALL RADBG (IDO,IP,L1,IDL1,C,C,C,CH,CH,WA(IW)) GO TO 114 113 CALL RADBG (IDO,IP,L1,IDL1,CH,CH,CH,C,C,WA(IW)) 114 IF (IDO .EQ. 1) NA = 1-NA 115 L1 = L2 IW = IW+(IP-1)*IDO 116 CONTINUE IF (NA .EQ. 0) RETURN DO 117 I=1,N C(I) = CH(I) 117 CONTINUE RETURN END