--- rpl/lapack/lapack/zlangb.f 2014/01/27 09:28:38 1.13 +++ rpl/lapack/lapack/zlangb.f 2020/05/21 21:46:07 1.18 @@ -2,25 +2,25 @@ * * =========== 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 ZLANGB + dependencies -*> -*> [TGZ] -*> -*> [ZIP] -*> +*> Download ZLANGB + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> *> [TXT] -*> \endhtmlonly +*> \endhtmlonly * * Definition: * =========== * * DOUBLE PRECISION FUNCTION ZLANGB( NORM, N, KL, KU, AB, LDAB, * WORK ) -* +* * .. Scalar Arguments .. * CHARACTER NORM * INTEGER KL, KU, LDAB, N @@ -29,7 +29,7 @@ * DOUBLE PRECISION WORK( * ) * COMPLEX*16 AB( LDAB, * ) * .. -* +* * *> \par Purpose: * ============= @@ -112,12 +112,12 @@ * 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 complex16GBauxiliary * @@ -125,11 +125,12 @@ DOUBLE PRECISION FUNCTION ZLANGB( NORM, N, KL, KU, AB, LDAB, $ 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 INTEGER KL, KU, LDAB, N @@ -147,14 +148,17 @@ * .. * .. Local Scalars .. INTEGER I, J, K, L - DOUBLE PRECISION SCALE, SUM, VALUE, TEMP + DOUBLE PRECISION SUM, VALUE, TEMP +* .. +* .. Local Arrays .. + DOUBLE PRECISION SSQ( 2 ), COLSSQ( 2 ) * .. * .. External Functions .. LOGICAL LSAME, DISNAN EXTERNAL LSAME, DISNAN * .. * .. External Subroutines .. - EXTERNAL ZLASSQ + EXTERNAL ZLASSQ, DCOMBSSQ * .. * .. Intrinsic Functions .. INTRINSIC ABS, MAX, MIN, SQRT @@ -207,15 +211,22 @@ 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. * - SCALE = ZERO - SUM = ONE + SSQ( 1 ) = ZERO + SSQ( 2 ) = ONE DO 90 J = 1, N L = MAX( 1, J-KU ) K = KU + 1 - J + L - CALL ZLASSQ( MIN( N, J+KL )-L+1, AB( K, J ), 1, SCALE, SUM ) + COLSSQ( 1 ) = ZERO + COLSSQ( 2 ) = ONE + CALL ZLASSQ( MIN( N, J+KL )-L+1, AB( K, J ), 1, + $ COLSSQ( 1 ), COLSSQ( 2 ) ) + CALL DCOMBSSQ( SSQ, COLSSQ ) 90 CONTINUE - VALUE = SCALE*SQRT( SUM ) + VALUE = SSQ( 1 )*SQRT( SSQ( 2 ) ) END IF * ZLANGB = VALUE