version 1.11, 2012/12/14 12:30:23
|
version 1.18, 2020/05/21 21:45:59
|
Line 2
|
Line 2
|
* |
* |
* =========== DOCUMENTATION =========== |
* =========== DOCUMENTATION =========== |
* |
* |
* Online html documentation available at |
* Online html documentation available at |
* http://www.netlib.org/lapack/explore-html/ |
* http://www.netlib.org/lapack/explore-html/ |
* |
* |
*> \htmlonly |
*> \htmlonly |
*> Download DLANSB + dependencies |
*> Download DLANSB + dependencies |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlansb.f"> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlansb.f"> |
*> [TGZ]</a> |
*> [TGZ]</a> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlansb.f"> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlansb.f"> |
*> [ZIP]</a> |
*> [ZIP]</a> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlansb.f"> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlansb.f"> |
*> [TXT]</a> |
*> [TXT]</a> |
*> \endhtmlonly |
*> \endhtmlonly |
* |
* |
* Definition: |
* Definition: |
* =========== |
* =========== |
* |
* |
* DOUBLE PRECISION FUNCTION DLANSB( NORM, UPLO, N, K, AB, LDAB, |
* DOUBLE PRECISION FUNCTION DLANSB( NORM, UPLO, N, K, AB, LDAB, |
* WORK ) |
* WORK ) |
* |
* |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
* CHARACTER NORM, UPLO |
* CHARACTER NORM, UPLO |
* INTEGER K, LDAB, N |
* INTEGER K, LDAB, N |
Line 28
|
Line 28
|
* .. Array Arguments .. |
* .. Array Arguments .. |
* DOUBLE PRECISION AB( LDAB, * ), WORK( * ) |
* DOUBLE PRECISION AB( LDAB, * ), WORK( * ) |
* .. |
* .. |
* |
* |
* |
* |
*> \par Purpose: |
*> \par Purpose: |
* ============= |
* ============= |
Line 116
|
Line 116
|
* Authors: |
* Authors: |
* ======== |
* ======== |
* |
* |
*> \author Univ. of Tennessee |
*> \author Univ. of Tennessee |
*> \author Univ. of California Berkeley |
*> \author Univ. of California Berkeley |
*> \author Univ. of Colorado Denver |
*> \author Univ. of Colorado Denver |
*> \author NAG Ltd. |
*> \author NAG Ltd. |
* |
* |
*> \date September 2012 |
*> \date December 2016 |
* |
* |
*> \ingroup doubleOTHERauxiliary |
*> \ingroup doubleOTHERauxiliary |
* |
* |
Line 129
|
Line 129
|
DOUBLE PRECISION FUNCTION DLANSB( NORM, UPLO, N, K, AB, LDAB, |
DOUBLE PRECISION FUNCTION DLANSB( NORM, UPLO, N, K, AB, LDAB, |
$ WORK ) |
$ WORK ) |
* |
* |
* -- LAPACK auxiliary routine (version 3.4.2) -- |
* -- LAPACK auxiliary routine (version 3.7.0) -- |
* -- LAPACK is a software package provided by Univ. of Tennessee, -- |
* -- LAPACK is a software package provided by Univ. of Tennessee, -- |
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
* September 2012 |
* December 2016 |
* |
* |
|
IMPLICIT NONE |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
CHARACTER NORM, UPLO |
CHARACTER NORM, UPLO |
INTEGER K, LDAB, N |
INTEGER K, LDAB, N |
Line 150
|
Line 151
|
* .. |
* .. |
* .. Local Scalars .. |
* .. Local Scalars .. |
INTEGER I, J, L |
INTEGER I, J, L |
DOUBLE PRECISION ABSA, SCALE, SUM, VALUE |
DOUBLE PRECISION ABSA, SUM, VALUE |
* .. |
* .. |
* .. External Subroutines .. |
* .. Local Arrays .. |
EXTERNAL DLASSQ |
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 DLASSQ, DCOMBSSQ |
|
* .. |
* .. Intrinsic Functions .. |
* .. Intrinsic Functions .. |
INTRINSIC ABS, MAX, MIN, SQRT |
INTRINSIC ABS, MAX, MIN, SQRT |
* .. |
* .. |
Line 225
|
Line 229
|
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 DLASSQ( MIN( J-1, K ), AB( MAX( K+2-J, 1 ), J ), |
CALL DLASSQ( 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 DLASSQ( MIN( N-J, K ), AB( 2, J ), 1, SCALE, |
COLSSQ( 1 ) = ZERO |
$ SUM ) |
COLSSQ( 2 ) = ONE |
|
CALL DLASSQ( 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 DLASSQ( N, AB( L, 1 ), LDAB, SCALE, SUM ) |
* |
VALUE = SCALE*SQRT( SUM ) |
* Sum diagonal |
|
* |
|
COLSSQ( 1 ) = ZERO |
|
COLSSQ( 2 ) = ONE |
|
CALL DLASSQ( N, AB( L, 1 ), LDAB, COLSSQ( 1 ), COLSSQ( 2 ) ) |
|
CALL DCOMBSSQ( SSQ, COLSSQ ) |
|
VALUE = SSQ( 1 )*SQRT( SSQ( 2 ) ) |
END IF |
END IF |
* |
* |
DLANSB = VALUE |
DLANSB = VALUE |