diff --git a/SRC/chgeqz.f b/SRC/chgeqz.f index 73d35621c3..bcf5acd0bf 100644 --- a/SRC/chgeqz.f +++ b/SRC/chgeqz.f @@ -319,13 +319,14 @@ SUBROUTINE CHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, REAL ABSB, ANORM, ASCALE, ATOL, BNORM, BSCALE, BTOL, $ C, SAFMIN, TEMP, TEMP2, TEMPR, ULP COMPLEX ABI22, AD11, AD12, AD21, AD22, CTEMP, CTEMP2, - $ CTEMP3, ESHIFT, RTDISC, S, SHIFT, SIGNBC, T1, - $ U12, X + $ CTEMP3, ESHIFT, S, SHIFT, SIGNBC, + $ U12, X, ABI12, Y * .. * .. External Functions .. + COMPLEX CLADIV LOGICAL LSAME REAL CLANHS, SLAMCH - EXTERNAL LSAME, CLANHS, SLAMCH + EXTERNAL CLADIV, LSAME, CLANHS, SLAMCH * .. * .. External Subroutines .. EXTERNAL CLARTG, CLASET, CROT, CSCAL, XERBLA @@ -350,6 +351,7 @@ SUBROUTINE CHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, ILSCHR = .TRUE. ISCHUR = 2 ELSE + ILSCHR = .TRUE. ISCHUR = 0 END IF * @@ -363,6 +365,7 @@ SUBROUTINE CHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, ILQ = .TRUE. ICOMPQ = 3 ELSE + ILQ = .TRUE. ICOMPQ = 0 END IF * @@ -376,6 +379,7 @@ SUBROUTINE CHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, ILZ = .TRUE. ICOMPZ = 3 ELSE + ILZ = .TRUE. ICOMPZ = 0 END IF * @@ -729,22 +733,34 @@ SUBROUTINE CHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, AD22 = ( ASCALE*H( ILAST, ILAST ) ) / $ ( BSCALE*T( ILAST, ILAST ) ) ABI22 = AD22 - U12*AD21 + ABI12 = AD12 - U12*AD11 * - T1 = HALF*( AD11+ABI22 ) - RTDISC = SQRT( T1**2+AD12*AD21-AD11*AD22 ) - TEMP = REAL( T1-ABI22 )*REAL( RTDISC ) + - $ AIMAG( T1-ABI22 )*AIMAG( RTDISC ) - IF( TEMP.LE.ZERO ) THEN - SHIFT = T1 + RTDISC - ELSE - SHIFT = T1 - RTDISC + SHIFT = ABI22 + CTEMP = SQRT( ABI12 )*SQRT( AD21 ) + TEMP = ABS1( CTEMP ) + IF( CTEMP.NE.ZERO ) THEN + X = HALF*( AD11-SHIFT ) + TEMP2 = ABS1( X ) + TEMP = MAX( TEMP, ABS1( X ) ) + Y = TEMP*SQRT( ( X / TEMP )**2+( CTEMP / TEMP )**2 ) + IF( TEMP2.GT.ZERO ) THEN + IF( REAL( X / TEMP2 )*REAL( Y )+ + $ AIMAG( X / TEMP2 )*AIMAG( Y ).LT.ZERO )Y = -Y + END IF + SHIFT = SHIFT - CTEMP*CLADIV( CTEMP, ( X+Y ) ) END IF ELSE * * Exceptional shift. Chosen for no particularly good reason. * - ESHIFT = ESHIFT + (ASCALE*H(ILAST,ILAST-1))/ - $ (BSCALE*T(ILAST-1,ILAST-1)) + IF( ( IITER / 20 )*20.EQ.IITER .AND. + $ BSCALE*ABS1(T( ILAST, ILAST )).GT.SAFMIN ) THEN + ESHIFT = ESHIFT + ( ASCALE*H( ILAST, + $ ILAST ) )/( BSCALE*T( ILAST, ILAST ) ) + ELSE + ESHIFT = ESHIFT + ( ASCALE*H( ILAST, + $ ILAST-1 ) )/( BSCALE*T( ILAST-1, ILAST-1 ) ) + END IF SHIFT = ESHIFT END IF * diff --git a/SRC/zhgeqz.f b/SRC/zhgeqz.f index b51cba4f72..9602447272 100644 --- a/SRC/zhgeqz.f +++ b/SRC/zhgeqz.f @@ -319,13 +319,14 @@ SUBROUTINE ZHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, DOUBLE PRECISION ABSB, ANORM, ASCALE, ATOL, BNORM, BSCALE, BTOL, $ C, SAFMIN, TEMP, TEMP2, TEMPR, ULP COMPLEX*16 ABI22, AD11, AD12, AD21, AD22, CTEMP, CTEMP2, - $ CTEMP3, ESHIFT, RTDISC, S, SHIFT, SIGNBC, T1, - $ U12, X + $ CTEMP3, ESHIFT, S, SHIFT, SIGNBC, + $ U12, X, ABI12, Y * .. * .. External Functions .. + COMPLEX*16 ZLADIV LOGICAL LSAME DOUBLE PRECISION DLAMCH, ZLANHS - EXTERNAL LSAME, DLAMCH, ZLANHS + EXTERNAL ZLADIV, LSAME, DLAMCH, ZLANHS * .. * .. External Subroutines .. EXTERNAL XERBLA, ZLARTG, ZLASET, ZROT, ZSCAL @@ -351,6 +352,7 @@ SUBROUTINE ZHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, ILSCHR = .TRUE. ISCHUR = 2 ELSE + ILSCHR = .TRUE. ISCHUR = 0 END IF * @@ -364,6 +366,7 @@ SUBROUTINE ZHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, ILQ = .TRUE. ICOMPQ = 3 ELSE + ILQ = .TRUE. ICOMPQ = 0 END IF * @@ -377,6 +380,7 @@ SUBROUTINE ZHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, ILZ = .TRUE. ICOMPZ = 3 ELSE + ILZ = .TRUE. ICOMPZ = 0 END IF * @@ -730,22 +734,34 @@ SUBROUTINE ZHGEQZ( JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, AD22 = ( ASCALE*H( ILAST, ILAST ) ) / $ ( BSCALE*T( ILAST, ILAST ) ) ABI22 = AD22 - U12*AD21 + ABI12 = AD12 - U12*AD11 * - T1 = HALF*( AD11+ABI22 ) - RTDISC = SQRT( T1**2+AD12*AD21-AD11*AD22 ) - TEMP = DBLE( T1-ABI22 )*DBLE( RTDISC ) + - $ DIMAG( T1-ABI22 )*DIMAG( RTDISC ) - IF( TEMP.LE.ZERO ) THEN - SHIFT = T1 + RTDISC - ELSE - SHIFT = T1 - RTDISC + SHIFT = ABI22 + CTEMP = SQRT( ABI12 )*SQRT( AD21 ) + TEMP = ABS1( CTEMP ) + IF( CTEMP.NE.ZERO ) THEN + X = HALF*( AD11-SHIFT ) + TEMP2 = ABS1( X ) + TEMP = MAX( TEMP, ABS1( X ) ) + Y = TEMP*SQRT( ( X / TEMP )**2+( CTEMP / TEMP )**2 ) + IF( TEMP2.GT.ZERO ) THEN + IF( DBLE( X / TEMP2 )*DBLE( Y )+ + $ DIMAG( X / TEMP2 )*DIMAG( Y ).LT.ZERO )Y = -Y + END IF + SHIFT = SHIFT - CTEMP*ZLADIV( CTEMP, ( X+Y ) ) END IF ELSE * * Exceptional shift. Chosen for no particularly good reason. * - ESHIFT = ESHIFT + (ASCALE*H(ILAST,ILAST-1))/ - $ (BSCALE*T(ILAST-1,ILAST-1)) + IF( ( IITER / 20 )*20.EQ.IITER .AND. + $ BSCALE*ABS1(T( ILAST, ILAST )).GT.SAFMIN ) THEN + ESHIFT = ESHIFT + ( ASCALE*H( ILAST, + $ ILAST ) )/( BSCALE*T( ILAST, ILAST ) ) + ELSE + ESHIFT = ESHIFT + ( ASCALE*H( ILAST, + $ ILAST-1 ) )/( BSCALE*T( ILAST-1, ILAST-1 ) ) + END IF SHIFT = ESHIFT END IF *