--- rpl/lapack/lapack/zsytf2.f 2012/12/14 12:30:34 1.12 +++ rpl/lapack/lapack/zsytf2.f 2017/06/17 10:54:29 1.17 @@ -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 ZSYTF2 + dependencies -*> -*> [TGZ] -*> -*> [ZIP] -*> +*> Download ZSYTF2 + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> *> [TXT] -*> \endhtmlonly +*> \endhtmlonly * * Definition: * =========== * * SUBROUTINE ZSYTF2( UPLO, N, A, LDA, IPIV, INFO ) -* +* * .. Scalar Arguments .. * CHARACTER UPLO * INTEGER INFO, LDA, N @@ -28,7 +28,7 @@ * INTEGER IPIV( * ) * COMPLEX*16 A( LDA, * ) * .. -* +* * *> \par Purpose: * ============= @@ -90,13 +90,22 @@ *> \verbatim *> IPIV is INTEGER array, dimension (N) *> Details of the interchanges and the block structure of D. -*> If IPIV(k) > 0, then rows and columns k and IPIV(k) were -*> interchanged and D(k,k) is a 1-by-1 diagonal block. -*> If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0, then rows and -*> columns k-1 and -IPIV(k) were interchanged and D(k-1:k,k-1:k) -*> is a 2-by-2 diagonal block. If UPLO = 'L' and IPIV(k) = -*> IPIV(k+1) < 0, then rows and columns k+1 and -IPIV(k) were -*> interchanged and D(k:k+1,k:k+1) is a 2-by-2 diagonal block. +*> +*> If UPLO = 'U': +*> If IPIV(k) > 0, then rows and columns k and IPIV(k) were +*> interchanged and D(k,k) is a 1-by-1 diagonal block. +*> +*> If IPIV(k) = IPIV(k-1) < 0, then rows and columns +*> k-1 and -IPIV(k) were interchanged and D(k-1:k,k-1:k) +*> is a 2-by-2 diagonal block. +*> +*> If UPLO = 'L': +*> If IPIV(k) > 0, then rows and columns k and IPIV(k) were +*> interchanged and D(k,k) is a 1-by-1 diagonal block. +*> +*> If IPIV(k) = IPIV(k+1) < 0, then rows and columns +*> k+1 and -IPIV(k) were interchanged and D(k:k+1,k:k+1) +*> is a 2-by-2 diagonal block. *> \endverbatim *> *> \param[out] INFO @@ -113,12 +122,12 @@ * 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 complex16SYcomputational * @@ -182,10 +191,10 @@ * ===================================================================== SUBROUTINE ZSYTF2( UPLO, N, A, LDA, IPIV, INFO ) * -* -- LAPACK computational routine (version 3.4.2) -- +* -- LAPACK computational 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 * * .. Scalar Arguments .. CHARACTER UPLO @@ -273,7 +282,8 @@ ABSAKK = CABS1( A( K, K ) ) * * IMAX is the row-index of the largest off-diagonal element in -* column K, and COLMAX is its absolute value +* column K, and COLMAX is its absolute value. +* Determine both COLMAX and IMAX. * IF( K.GT.1 ) THEN IMAX = IZAMAX( K-1, A( 1, K ), 1 ) @@ -284,7 +294,8 @@ * IF( MAX( ABSAKK, COLMAX ).EQ.ZERO .OR. DISNAN(ABSAKK) ) THEN * -* Column K is zero or NaN: set INFO and continue +* Column K is zero or underflow, or contains a NaN: +* set INFO and continue * IF( INFO.EQ.0 ) $ INFO = K @@ -441,7 +452,8 @@ ABSAKK = CABS1( A( K, K ) ) * * IMAX is the row-index of the largest off-diagonal element in -* column K, and COLMAX is its absolute value +* column K, and COLMAX is its absolute value. +* Determine both COLMAX and IMAX. * IF( K.LT.N ) THEN IMAX = K + IZAMAX( N-K, A( K+1, K ), 1 ) @@ -452,7 +464,8 @@ * IF( MAX( ABSAKK, COLMAX ).EQ.ZERO .OR. DISNAN(ABSAKK) ) THEN * -* Column K is zero or NaN: set INFO and continue +* Column K is zero or underflow, or contains a NaN: +* set INFO and continue * IF( INFO.EQ.0 ) $ INFO = K