SUBROUTINE MFFTA9(C,FAC)**   PURPOSE:*       ELEMENTARY COOLEY-TUKEY RADIX-2 STEP APPLIED TO A VECTOR-OF-*       2-VECTORS-OF-COMPLEX [IMS,NM [IVS,NV [IES,NE]]], OPTIMIZED FOR*       SMALL NE MATRICES.*       SEE REF.[1] FOR NOTATIONS.*       THIS ROUTINE CAN BE USED ONLY BY ROUTINE MFFTIM, WHICH CONTROLS*       ITS OPERATION THROUGH COMMON MFFTPA.*      COMMON /MFFTPA/  IMS,IVS,IES,NM,NV,NE,MX,LX,MLIM,MSTEP,LLIM,LSTEP,     $ NUSTEP,IVLIM,ILIM,MD2LIM,LD2LIM      INTEGER NUSTEP      COMPLEX C(0:NUSTEP-1,0:1),FAC(0:*),T0*      IF(LX.NE.1) THEN*      DO 200 MU=0,MLIM,MSTEP        DO 150 IV=MU,MU+IVLIM,IVS          ILAMF=0          DO 100 ILAM=IV,IV+ILIM            T0=C(ILAM,1)*FAC(ILAMF)            C(ILAM,1)=C(ILAM,0)-T0            C(ILAM,0)=C(ILAM,0)+T0            ILAMF=ILAMF+1100       CONTINUE150     CONTINUE200   CONTINUE*      ELSE      DO 400 MU=0,MLIM,MSTEP        DO 350 IV=MU,MU+IVLIM,IVS          DO 300 ILAM=IV,IV+ILIM          T0=C(ILAM,1)          C(ILAM,1)=C(ILAM,0)-T0          C(ILAM,0)=C(ILAM,0)+T0 300      CONTINUE 350    CONTINUE 400  CONTINUE      ENDIF*      END