--- rpl/lapack/lapack/dlansp.f 2014/01/27 09:28:20 1.13 +++ rpl/lapack/lapack/dlansp.f 2020/05/21 21:45:59 1.18 @@ -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 DLANSP + dependencies -*> -*> [TGZ] -*> -*> [ZIP] -*> +*> Download DLANSP + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> *> [TXT] -*> \endhtmlonly +*> \endhtmlonly * * Definition: * =========== * * DOUBLE PRECISION FUNCTION DLANSP( NORM, UPLO, N, AP, WORK ) -* +* * .. Scalar Arguments .. * CHARACTER NORM, UPLO * INTEGER N @@ -27,7 +27,7 @@ * .. Array Arguments .. * DOUBLE PRECISION AP( * ), WORK( * ) * .. -* +* * *> \par Purpose: * ============= @@ -102,23 +102,24 @@ * 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 September 2012 +*> \date December 2016 * *> \ingroup doubleOTHERauxiliary * * ===================================================================== DOUBLE PRECISION FUNCTION DLANSP( NORM, UPLO, N, AP, 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, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* September 2012 +* December 2016 * + IMPLICIT NONE * .. Scalar Arguments .. CHARACTER NORM, UPLO INTEGER N @@ -135,15 +136,18 @@ * .. * .. Local Scalars .. INTEGER I, J, K - 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 * .. @@ -217,31 +221,48 @@ 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 K = 2 IF( LSAME( UPLO, 'U' ) ) THEN DO 110 J = 2, N - CALL DLASSQ( J-1, AP( K ), 1, SCALE, SUM ) + COLSSQ( 1 ) = ZERO + COLSSQ( 2 ) = ONE + CALL DLASSQ( J-1, AP( K ), 1, COLSSQ( 1 ), COLSSQ( 2 ) ) + CALL DCOMBSSQ( SSQ, COLSSQ ) K = K + J 110 CONTINUE ELSE DO 120 J = 1, N - 1 - CALL DLASSQ( N-J, AP( K ), 1, SCALE, SUM ) + COLSSQ( 1 ) = ZERO + COLSSQ( 2 ) = ONE + CALL DLASSQ( N-J, AP( K ), 1, COLSSQ( 1 ), COLSSQ( 2 ) ) + CALL DCOMBSSQ( SSQ, COLSSQ ) K = K + N - J + 1 120 CONTINUE END IF - SUM = 2*SUM + SSQ( 2 ) = 2*SSQ( 2 ) +* +* Sum diagonal +* K = 1 + COLSSQ( 1 ) = ZERO + COLSSQ( 2 ) = ONE DO 130 I = 1, N IF( AP( K ).NE.ZERO ) THEN ABSA = ABS( AP( K ) ) - IF( SCALE.LT.ABSA ) THEN - SUM = ONE + SUM*( SCALE / ABSA )**2 - SCALE = ABSA + IF( COLSSQ( 1 ).LT.ABSA ) THEN + COLSSQ( 2 ) = ONE + COLSSQ(2)*( COLSSQ(1) / ABSA )**2 + COLSSQ( 1 ) = ABSA ELSE - SUM = SUM + ( ABSA / SCALE )**2 + COLSSQ( 2 ) = COLSSQ( 2 ) + ( ABSA / COLSSQ( 1 ) )**2 END IF END IF IF( LSAME( UPLO, 'U' ) ) THEN @@ -250,7 +271,8 @@ K = K + N - I + 1 END IF 130 CONTINUE - VALUE = SCALE*SQRT( SUM ) + CALL DCOMBSSQ( SSQ, COLSSQ ) + VALUE = SSQ( 1 )*SQRT( SSQ( 2 ) ) END IF * DLANSP = VALUE