version 1.9, 2011/11/21 22:19:32
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version 1.19, 2023/08/07 08:38:55
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*> \brief \b DLANHS |
*> \brief \b DLANHS returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of an upper Hessenberg matrix. |
* |
* |
* =========== 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 DLANHS + dependencies |
*> Download DLANHS + dependencies |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlanhs.f"> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlanhs.f"> |
*> [TGZ]</a> |
*> [TGZ]</a> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlanhs.f"> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlanhs.f"> |
*> [ZIP]</a> |
*> [ZIP]</a> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlanhs.f"> |
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlanhs.f"> |
*> [TXT]</a> |
*> [TXT]</a> |
*> \endhtmlonly |
*> \endhtmlonly |
* |
* |
* Definition: |
* Definition: |
* =========== |
* =========== |
* |
* |
* DOUBLE PRECISION FUNCTION DLANHS( NORM, N, A, LDA, WORK ) |
* DOUBLE PRECISION FUNCTION DLANHS( NORM, N, A, LDA, WORK ) |
* |
* |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
* CHARACTER NORM |
* CHARACTER NORM |
* INTEGER LDA, N |
* INTEGER LDA, N |
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* .. Array Arguments .. |
* .. Array Arguments .. |
* DOUBLE PRECISION A( LDA, * ), WORK( * ) |
* DOUBLE PRECISION A( LDA, * ), WORK( * ) |
* .. |
* .. |
* |
* |
* |
* |
*> \par Purpose: |
*> \par Purpose: |
* ============= |
* ============= |
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* 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 November 2011 |
|
* |
* |
*> \ingroup doubleOTHERauxiliary |
*> \ingroup doubleOTHERauxiliary |
* |
* |
* ===================================================================== |
* ===================================================================== |
DOUBLE PRECISION FUNCTION DLANHS( NORM, N, A, LDA, WORK ) |
DOUBLE PRECISION FUNCTION DLANHS( NORM, N, A, LDA, WORK ) |
* |
* |
* -- LAPACK auxiliary routine (version 3.4.0) -- |
* -- LAPACK auxiliary routine -- |
* -- 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..-- |
* November 2011 |
|
* |
* |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
CHARACTER NORM |
CHARACTER NORM |
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EXTERNAL DLASSQ |
EXTERNAL DLASSQ |
* .. |
* .. |
* .. External Functions .. |
* .. External Functions .. |
LOGICAL LSAME |
LOGICAL LSAME, DISNAN |
EXTERNAL LSAME |
EXTERNAL LSAME, DISNAN |
* .. |
* .. |
* .. Intrinsic Functions .. |
* .. Intrinsic Functions .. |
INTRINSIC ABS, MAX, MIN, SQRT |
INTRINSIC ABS, MIN, SQRT |
* .. |
* .. |
* .. Executable Statements .. |
* .. Executable Statements .. |
* |
* |
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VALUE = ZERO |
VALUE = ZERO |
DO 20 J = 1, N |
DO 20 J = 1, N |
DO 10 I = 1, MIN( N, J+1 ) |
DO 10 I = 1, MIN( N, J+1 ) |
VALUE = MAX( VALUE, ABS( A( I, J ) ) ) |
SUM = ABS( A( I, J ) ) |
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IF( VALUE .LT. SUM .OR. DISNAN( SUM ) ) VALUE = SUM |
10 CONTINUE |
10 CONTINUE |
20 CONTINUE |
20 CONTINUE |
ELSE IF( ( LSAME( NORM, 'O' ) ) .OR. ( NORM.EQ.'1' ) ) THEN |
ELSE IF( ( LSAME( NORM, 'O' ) ) .OR. ( NORM.EQ.'1' ) ) THEN |
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DO 30 I = 1, MIN( N, J+1 ) |
DO 30 I = 1, MIN( N, J+1 ) |
SUM = SUM + ABS( A( I, J ) ) |
SUM = SUM + ABS( A( I, J ) ) |
30 CONTINUE |
30 CONTINUE |
VALUE = MAX( VALUE, SUM ) |
IF( VALUE .LT. SUM .OR. DISNAN( SUM ) ) VALUE = SUM |
40 CONTINUE |
40 CONTINUE |
ELSE IF( LSAME( NORM, 'I' ) ) THEN |
ELSE IF( LSAME( NORM, 'I' ) ) THEN |
* |
* |
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70 CONTINUE |
70 CONTINUE |
VALUE = ZERO |
VALUE = ZERO |
DO 80 I = 1, N |
DO 80 I = 1, N |
VALUE = MAX( VALUE, WORK( I ) ) |
SUM = WORK( I ) |
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IF( VALUE .LT. SUM .OR. DISNAN( SUM ) ) VALUE = SUM |
80 CONTINUE |
80 CONTINUE |
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN |
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN |
* |
* |