--- rpl/lapack/lapack/dlansy.f 2016/08/27 15:34:28 1.15
+++ rpl/lapack/lapack/dlansy.f 2020/05/21 21:45:59 1.19
@@ -2,24 +2,24 @@
*
* =========== DOCUMENTATION ===========
*
-* Online html documentation available at
-* http://www.netlib.org/lapack/explore-html/
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
*
*> \htmlonly
-*> Download DLANSY + dependencies
-*>
-*> [TGZ]
-*>
-*> [ZIP]
-*>
+*> Download DLANSY + dependencies
+*>
+*> [TGZ]
+*>
+*> [ZIP]
+*>
*> [TXT]
-*> \endhtmlonly
+*> \endhtmlonly
*
* Definition:
* ===========
*
* DOUBLE PRECISION FUNCTION DLANSY( NORM, UPLO, N, A, LDA, WORK )
-*
+*
* .. Scalar Arguments ..
* CHARACTER NORM, UPLO
* INTEGER LDA, N
@@ -27,7 +27,7 @@
* .. Array Arguments ..
* DOUBLE PRECISION A( LDA, * ), WORK( * )
* ..
-*
+*
*
*> \par Purpose:
* =============
@@ -110,23 +110,24 @@
* Authors:
* ========
*
-*> \author Univ. of Tennessee
-*> \author Univ. of California Berkeley
-*> \author Univ. of Colorado Denver
-*> \author NAG Ltd.
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
*
-*> \date November 2015
+*> \date December 2016
*
*> \ingroup doubleSYauxiliary
*
* =====================================================================
DOUBLE PRECISION FUNCTION DLANSY( NORM, UPLO, N, A, LDA, WORK )
*
-* -- LAPACK auxiliary routine (version 3.6.0) --
+* -- LAPACK auxiliary routine (version 3.7.0) --
* -- LAPACK is a software package provided by Univ. of Tennessee, --
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
-* November 2015
+* December 2016
*
+ IMPLICIT NONE
* .. Scalar Arguments ..
CHARACTER NORM, UPLO
INTEGER LDA, N
@@ -143,15 +144,18 @@
* ..
* .. Local Scalars ..
INTEGER I, J
- DOUBLE PRECISION ABSA, SCALE, SUM, VALUE
+ DOUBLE PRECISION ABSA, SUM, VALUE
* ..
-* .. External Subroutines ..
- EXTERNAL DLASSQ
+* .. Local Arrays ..
+ DOUBLE PRECISION SSQ( 2 ), COLSSQ( 2 )
* ..
* .. External Functions ..
LOGICAL LSAME, DISNAN
EXTERNAL LSAME, DISNAN
* ..
+* .. External Subroutines ..
+ EXTERNAL DLASSQ, DCOMBSSQ
+* ..
* .. Intrinsic Functions ..
INTRINSIC ABS, SQRT
* ..
@@ -216,21 +220,39 @@
ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN
*
* 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( LSAME( UPLO, 'U' ) ) THEN
DO 110 J = 2, N
- CALL DLASSQ( J-1, A( 1, J ), 1, SCALE, SUM )
+ COLSSQ( 1 ) = ZERO
+ COLSSQ( 2 ) = ONE
+ CALL DLASSQ( J-1, A( 1, J ), 1, COLSSQ(1), COLSSQ(2) )
+ CALL DCOMBSSQ( SSQ, COLSSQ )
110 CONTINUE
ELSE
DO 120 J = 1, N - 1
- CALL DLASSQ( N-J, A( J+1, J ), 1, SCALE, SUM )
+ COLSSQ( 1 ) = ZERO
+ COLSSQ( 2 ) = ONE
+ CALL DLASSQ( N-J, A( J+1, J ), 1, COLSSQ(1), COLSSQ(2) )
+ CALL DCOMBSSQ( SSQ, COLSSQ )
120 CONTINUE
END IF
- SUM = 2*SUM
- CALL DLASSQ( N, A, LDA+1, SCALE, SUM )
- VALUE = SCALE*SQRT( SUM )
+ SSQ( 2 ) = 2*SSQ( 2 )
+*
+* Sum diagonal
+*
+ COLSSQ( 1 ) = ZERO
+ COLSSQ( 2 ) = ONE
+ CALL DLASSQ( N, A, LDA+1, COLSSQ( 1 ), COLSSQ( 2 ) )
+ CALL DCOMBSSQ( SSQ, COLSSQ )
+ VALUE = SSQ( 1 )*SQRT( SSQ( 2 ) )
END IF
*
DLANSY = VALUE