version 1.10, 2012/08/22 09:48:18
|
version 1.11, 2012/12/14 12:30:23
|
Line 1
|
Line 1
|
*> \brief \b DLANST |
*> \brief \b DLANST returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real symmetric tridiagonal matrix. |
* |
* |
* =========== DOCUMENTATION =========== |
* =========== DOCUMENTATION =========== |
* |
* |
Line 93
|
Line 93
|
*> \author Univ. of Colorado Denver |
*> \author Univ. of Colorado Denver |
*> \author NAG Ltd. |
*> \author NAG Ltd. |
* |
* |
*> \date November 2011 |
*> \date September 2012 |
* |
* |
*> \ingroup auxOTHERauxiliary |
*> \ingroup auxOTHERauxiliary |
* |
* |
* ===================================================================== |
* ===================================================================== |
DOUBLE PRECISION FUNCTION DLANST( NORM, N, D, E ) |
DOUBLE PRECISION FUNCTION DLANST( NORM, N, D, E ) |
* |
* |
* -- LAPACK auxiliary routine (version 3.4.0) -- |
* -- LAPACK auxiliary routine (version 3.4.2) -- |
* -- 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 |
* September 2012 |
* |
* |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
CHARACTER NORM |
CHARACTER NORM |
Line 124
|
Line 124
|
DOUBLE PRECISION ANORM, SCALE, SUM |
DOUBLE PRECISION ANORM, SCALE, SUM |
* .. |
* .. |
* .. External Functions .. |
* .. External Functions .. |
LOGICAL LSAME |
LOGICAL LSAME, DISNAN |
EXTERNAL LSAME |
EXTERNAL LSAME, DISNAN |
* .. |
* .. |
* .. External Subroutines .. |
* .. External Subroutines .. |
EXTERNAL DLASSQ |
EXTERNAL DLASSQ |
* .. |
* .. |
* .. Intrinsic Functions .. |
* .. Intrinsic Functions .. |
INTRINSIC ABS, MAX, SQRT |
INTRINSIC ABS, SQRT |
* .. |
* .. |
* .. Executable Statements .. |
* .. Executable Statements .. |
* |
* |
Line 143
|
Line 143
|
* |
* |
ANORM = ABS( D( N ) ) |
ANORM = ABS( D( N ) ) |
DO 10 I = 1, N - 1 |
DO 10 I = 1, N - 1 |
ANORM = MAX( ANORM, ABS( D( I ) ) ) |
SUM = ABS( D( I ) ) |
ANORM = MAX( ANORM, ABS( E( I ) ) ) |
IF( ANORM .LT. SUM .OR. DISNAN( SUM ) ) ANORM = SUM |
|
SUM = ABS( E( I ) ) |
|
IF( ANORM .LT. SUM .OR. DISNAN( SUM ) ) ANORM = SUM |
10 CONTINUE |
10 CONTINUE |
ELSE IF( LSAME( NORM, 'O' ) .OR. NORM.EQ.'1' .OR. |
ELSE IF( LSAME( NORM, 'O' ) .OR. NORM.EQ.'1' .OR. |
$ LSAME( NORM, 'I' ) ) THEN |
$ LSAME( NORM, 'I' ) ) THEN |
Line 154
|
Line 156
|
IF( N.EQ.1 ) THEN |
IF( N.EQ.1 ) THEN |
ANORM = ABS( D( 1 ) ) |
ANORM = ABS( D( 1 ) ) |
ELSE |
ELSE |
ANORM = MAX( ABS( D( 1 ) )+ABS( E( 1 ) ), |
ANORM = ABS( D( 1 ) )+ABS( E( 1 ) ) |
$ ABS( E( N-1 ) )+ABS( D( N ) ) ) |
SUM = ABS( E( N-1 ) )+ABS( D( N ) ) |
|
IF( ANORM .LT. SUM .OR. DISNAN( SUM ) ) ANORM = SUM |
DO 20 I = 2, N - 1 |
DO 20 I = 2, N - 1 |
ANORM = MAX( ANORM, ABS( D( I ) )+ABS( E( I ) )+ |
SUM = ABS( D( I ) )+ABS( E( I ) )+ABS( E( I-1 ) ) |
$ ABS( E( I-1 ) ) ) |
IF( ANORM .LT. SUM .OR. DISNAN( SUM ) ) ANORM = SUM |
20 CONTINUE |
20 CONTINUE |
END IF |
END IF |
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN |
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN |