--- rpl/lapack/lapack/zgbtf2.f 2010/12/21 13:53:42 1.7 +++ rpl/lapack/lapack/zgbtf2.f 2011/11/21 20:43:08 1.8 @@ -1,9 +1,154 @@ +*> \brief \b ZGBTF2 +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download ZGBTF2 + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE ZGBTF2( M, N, KL, KU, AB, LDAB, IPIV, INFO ) +* +* .. Scalar Arguments .. +* INTEGER INFO, KL, KU, LDAB, M, N +* .. +* .. Array Arguments .. +* INTEGER IPIV( * ) +* COMPLEX*16 AB( LDAB, * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> ZGBTF2 computes an LU factorization of a complex m-by-n band matrix +*> A using partial pivoting with row interchanges. +*> +*> This is the unblocked version of the algorithm, calling Level 2 BLAS. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] M +*> \verbatim +*> M is INTEGER +*> The number of rows of the matrix A. M >= 0. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The number of columns of the matrix A. N >= 0. +*> \endverbatim +*> +*> \param[in] KL +*> \verbatim +*> KL is INTEGER +*> The number of subdiagonals within the band of A. KL >= 0. +*> \endverbatim +*> +*> \param[in] KU +*> \verbatim +*> KU is INTEGER +*> The number of superdiagonals within the band of A. KU >= 0. +*> \endverbatim +*> +*> \param[in,out] AB +*> \verbatim +*> AB is COMPLEX*16 array, dimension (LDAB,N) +*> On entry, the matrix A in band storage, in rows KL+1 to +*> 2*KL+KU+1; rows 1 to KL of the array need not be set. +*> The j-th column of A is stored in the j-th column of the +*> array AB as follows: +*> AB(kl+ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(m,j+kl) +*> +*> On exit, details of the factorization: U is stored as an +*> upper triangular band matrix with KL+KU superdiagonals in +*> rows 1 to KL+KU+1, and the multipliers used during the +*> factorization are stored in rows KL+KU+2 to 2*KL+KU+1. +*> See below for further details. +*> \endverbatim +*> +*> \param[in] LDAB +*> \verbatim +*> LDAB is INTEGER +*> The leading dimension of the array AB. LDAB >= 2*KL+KU+1. +*> \endverbatim +*> +*> \param[out] IPIV +*> \verbatim +*> IPIV is INTEGER array, dimension (min(M,N)) +*> The pivot indices; for 1 <= i <= min(M,N), row i of the +*> matrix was interchanged with row IPIV(i). +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit +*> < 0: if INFO = -i, the i-th argument had an illegal value +*> > 0: if INFO = +i, U(i,i) is exactly zero. The factorization +*> has been completed, but the factor U is exactly +*> singular, and division by zero will occur if it is used +*> to solve a system of equations. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup complex16GBcomputational +* +*> \par Further Details: +* ===================== +*> +*> \verbatim +*> +*> The band storage scheme is illustrated by the following example, when +*> M = N = 6, KL = 2, KU = 1: +*> +*> On entry: On exit: +*> +*> * * * + + + * * * u14 u25 u36 +*> * * + + + + * * u13 u24 u35 u46 +*> * a12 a23 a34 a45 a56 * u12 u23 u34 u45 u56 +*> a11 a22 a33 a44 a55 a66 u11 u22 u33 u44 u55 u66 +*> a21 a32 a43 a54 a65 * m21 m32 m43 m54 m65 * +*> a31 a42 a53 a64 * * m31 m42 m53 m64 * * +*> +*> Array elements marked * are not used by the routine; elements marked +*> + need not be set on entry, but are required by the routine to store +*> elements of U, because of fill-in resulting from the row +*> interchanges. +*> \endverbatim +*> +* ===================================================================== SUBROUTINE ZGBTF2( M, N, KL, KU, AB, LDAB, IPIV, INFO ) * -* -- LAPACK routine (version 3.2) -- +* -- LAPACK computational routine (version 3.4.0) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* November 2006 +* November 2011 * * .. Scalar Arguments .. INTEGER INFO, KL, KU, LDAB, M, N @@ -13,77 +158,6 @@ COMPLEX*16 AB( LDAB, * ) * .. * -* Purpose -* ======= -* -* ZGBTF2 computes an LU factorization of a complex m-by-n band matrix -* A using partial pivoting with row interchanges. -* -* This is the unblocked version of the algorithm, calling Level 2 BLAS. -* -* Arguments -* ========= -* -* M (input) INTEGER -* The number of rows of the matrix A. M >= 0. -* -* N (input) INTEGER -* The number of columns of the matrix A. N >= 0. -* -* KL (input) INTEGER -* The number of subdiagonals within the band of A. KL >= 0. -* -* KU (input) INTEGER -* The number of superdiagonals within the band of A. KU >= 0. -* -* AB (input/output) COMPLEX*16 array, dimension (LDAB,N) -* On entry, the matrix A in band storage, in rows KL+1 to -* 2*KL+KU+1; rows 1 to KL of the array need not be set. -* The j-th column of A is stored in the j-th column of the -* array AB as follows: -* AB(kl+ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(m,j+kl) -* -* On exit, details of the factorization: U is stored as an -* upper triangular band matrix with KL+KU superdiagonals in -* rows 1 to KL+KU+1, and the multipliers used during the -* factorization are stored in rows KL+KU+2 to 2*KL+KU+1. -* See below for further details. -* -* LDAB (input) INTEGER -* The leading dimension of the array AB. LDAB >= 2*KL+KU+1. -* -* IPIV (output) INTEGER array, dimension (min(M,N)) -* The pivot indices; for 1 <= i <= min(M,N), row i of the -* matrix was interchanged with row IPIV(i). -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* > 0: if INFO = +i, U(i,i) is exactly zero. The factorization -* has been completed, but the factor U is exactly -* singular, and division by zero will occur if it is used -* to solve a system of equations. -* -* Further Details -* =============== -* -* The band storage scheme is illustrated by the following example, when -* M = N = 6, KL = 2, KU = 1: -* -* On entry: On exit: -* -* * * * + + + * * * u14 u25 u36 -* * * + + + + * * u13 u24 u35 u46 -* * a12 a23 a34 a45 a56 * u12 u23 u34 u45 u56 -* a11 a22 a33 a44 a55 a66 u11 u22 u33 u44 u55 u66 -* a21 a32 a43 a54 a65 * m21 m32 m43 m54 m65 * -* a31 a42 a53 a64 * * m31 m42 m53 m64 * * -* -* Array elements marked * are not used by the routine; elements marked -* + need not be set on entry, but are required by the routine to store -* elements of U, because of fill-in resulting from the row -* interchanges. -* * ===================================================================== * * .. Parameters ..