--- rpl/lapack/lapack/dlange.f 2011/11/21 20:42:56 1.8 +++ rpl/lapack/lapack/dlange.f 2020/05/21 21:45:59 1.18 @@ -1,25 +1,25 @@ -*> \brief \b DLANGE +*> \brief \b DLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general rectangular matrix. * * =========== 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 DLANGE + dependencies -*> -*> [TGZ] -*> -*> [ZIP] -*> +*> Download DLANGE + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> *> [TXT] -*> \endhtmlonly +*> \endhtmlonly * * Definition: * =========== * * DOUBLE PRECISION FUNCTION DLANGE( NORM, M, N, A, LDA, WORK ) -* +* * .. Scalar Arguments .. * CHARACTER NORM * INTEGER LDA, M, N @@ -27,7 +27,7 @@ * .. Array Arguments .. * DOUBLE PRECISION A( LDA, * ), 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 November 2011 +*> \date December 2016 * *> \ingroup doubleGEauxiliary * * ===================================================================== DOUBLE PRECISION FUNCTION DLANGE( NORM, M, N, A, LDA, WORK ) * -* -- LAPACK auxiliary routine (version 3.4.0) -- +* -- 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 2011 +* December 2016 * + IMPLICIT NONE * .. Scalar Arguments .. CHARACTER NORM INTEGER LDA, M, N @@ -135,17 +136,20 @@ * .. * .. Local Scalars .. INTEGER I, J - DOUBLE PRECISION SCALE, SUM, VALUE + DOUBLE PRECISION SUM, VALUE, TEMP +* .. +* .. Local Arrays .. + DOUBLE PRECISION SSQ( 2 ), COLSSQ( 2 ) * .. * .. External Subroutines .. - EXTERNAL DLASSQ + EXTERNAL DLASSQ, DCOMBSSQ * .. * .. External Functions .. - LOGICAL LSAME - EXTERNAL LSAME + LOGICAL LSAME, DISNAN + EXTERNAL LSAME, DISNAN * .. * .. Intrinsic Functions .. - INTRINSIC ABS, MAX, MIN, SQRT + INTRINSIC ABS, MIN, SQRT * .. * .. Executable Statements .. * @@ -158,7 +162,8 @@ VALUE = ZERO DO 20 J = 1, N DO 10 I = 1, M - VALUE = MAX( VALUE, ABS( A( I, J ) ) ) + TEMP = ABS( A( I, J ) ) + IF( VALUE.LT.TEMP .OR. DISNAN( TEMP ) ) VALUE = TEMP 10 CONTINUE 20 CONTINUE ELSE IF( ( LSAME( NORM, 'O' ) ) .OR. ( NORM.EQ.'1' ) ) THEN @@ -171,7 +176,7 @@ DO 30 I = 1, M SUM = SUM + ABS( A( I, J ) ) 30 CONTINUE - VALUE = MAX( VALUE, SUM ) + IF( VALUE.LT.SUM .OR. DISNAN( SUM ) ) VALUE = SUM 40 CONTINUE ELSE IF( LSAME( NORM, 'I' ) ) THEN * @@ -187,18 +192,25 @@ 70 CONTINUE VALUE = ZERO DO 80 I = 1, M - VALUE = MAX( VALUE, WORK( I ) ) + TEMP = WORK( I ) + IF( VALUE.LT.TEMP .OR. DISNAN( TEMP ) ) VALUE = TEMP 80 CONTINUE 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 - CALL DLASSQ( M, A( 1, J ), 1, SCALE, SUM ) + COLSSQ( 1 ) = ZERO + COLSSQ( 2 ) = ONE + CALL DLASSQ( M, A( 1, J ), 1, COLSSQ( 1 ), COLSSQ( 2 ) ) + CALL DCOMBSSQ( SSQ, COLSSQ ) 90 CONTINUE - VALUE = SCALE*SQRT( SUM ) + VALUE = SSQ( 1 )*SQRT( SSQ( 2 ) ) END IF * DLANGE = VALUE