version 1.15, 2017/06/17 10:54:20
|
version 1.18, 2020/05/21 21:46:08
|
Line 135
|
Line 135
|
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
* December 2016 |
* December 2016 |
* |
* |
|
IMPLICIT NONE |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
CHARACTER NORM, UPLO |
CHARACTER NORM, UPLO |
INTEGER K, LDAB, N |
INTEGER K, LDAB, N |
Line 152
|
Line 153
|
* .. |
* .. |
* .. Local Scalars .. |
* .. Local Scalars .. |
INTEGER I, J, L |
INTEGER I, J, L |
DOUBLE PRECISION ABSA, SCALE, SUM, VALUE |
DOUBLE PRECISION ABSA, SUM, VALUE |
|
* .. |
|
* .. Local Arrays .. |
|
DOUBLE PRECISION SSQ( 2 ), COLSSQ( 2 ) |
* .. |
* .. |
* .. External Functions .. |
* .. External Functions .. |
LOGICAL LSAME, DISNAN |
LOGICAL LSAME, DISNAN |
EXTERNAL LSAME, DISNAN |
EXTERNAL LSAME, DISNAN |
* .. |
* .. |
* .. External Subroutines .. |
* .. External Subroutines .. |
EXTERNAL ZLASSQ |
EXTERNAL ZLASSQ, DCOMBSSQ |
* .. |
* .. |
* .. Intrinsic Functions .. |
* .. Intrinsic Functions .. |
INTRINSIC ABS, MAX, MIN, SQRT |
INTRINSIC ABS, MAX, MIN, SQRT |
Line 227
|
Line 231
|
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN |
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN |
* |
* |
* Find normF(A). |
* Find normF(A). |
|
* SSQ(1) is scale |
|
* SSQ(2) is sum-of-squares |
|
* For better accuracy, sum each column separately. |
|
* |
|
SSQ( 1 ) = ZERO |
|
SSQ( 2 ) = ONE |
|
* |
|
* Sum off-diagonals |
* |
* |
SCALE = ZERO |
|
SUM = ONE |
|
IF( K.GT.0 ) THEN |
IF( K.GT.0 ) THEN |
IF( LSAME( UPLO, 'U' ) ) THEN |
IF( LSAME( UPLO, 'U' ) ) THEN |
DO 110 J = 2, N |
DO 110 J = 2, N |
|
COLSSQ( 1 ) = ZERO |
|
COLSSQ( 2 ) = ONE |
CALL ZLASSQ( MIN( J-1, K ), AB( MAX( K+2-J, 1 ), J ), |
CALL ZLASSQ( MIN( J-1, K ), AB( MAX( K+2-J, 1 ), J ), |
$ 1, SCALE, SUM ) |
$ 1, COLSSQ( 1 ), COLSSQ( 2 ) ) |
|
CALL DCOMBSSQ( SSQ, COLSSQ ) |
110 CONTINUE |
110 CONTINUE |
L = K + 1 |
L = K + 1 |
ELSE |
ELSE |
DO 120 J = 1, N - 1 |
DO 120 J = 1, N - 1 |
CALL ZLASSQ( MIN( N-J, K ), AB( 2, J ), 1, SCALE, |
COLSSQ( 1 ) = ZERO |
$ SUM ) |
COLSSQ( 2 ) = ONE |
|
CALL ZLASSQ( MIN( N-J, K ), AB( 2, J ), 1, |
|
$ COLSSQ( 1 ), COLSSQ( 2 ) ) |
|
CALL DCOMBSSQ( SSQ, COLSSQ ) |
120 CONTINUE |
120 CONTINUE |
L = 1 |
L = 1 |
END IF |
END IF |
SUM = 2*SUM |
SSQ( 2 ) = 2*SSQ( 2 ) |
ELSE |
ELSE |
L = 1 |
L = 1 |
END IF |
END IF |
CALL ZLASSQ( N, AB( L, 1 ), LDAB, SCALE, SUM ) |
* |
VALUE = SCALE*SQRT( SUM ) |
* Sum diagonal |
|
* |
|
COLSSQ( 1 ) = ZERO |
|
COLSSQ( 2 ) = ONE |
|
CALL ZLASSQ( N, AB( L, 1 ), LDAB, COLSSQ( 1 ), COLSSQ( 2 ) ) |
|
CALL DCOMBSSQ( SSQ, COLSSQ ) |
|
VALUE = SSQ( 1 )*SQRT( SSQ( 2 ) ) |
END IF |
END IF |
* |
* |
ZLANSB = VALUE |
ZLANSB = VALUE |