--- rpl/lapack/lapack/zpbtf2.f 2011/07/22 07:38:18 1.8 +++ rpl/lapack/lapack/zpbtf2.f 2011/11/21 20:43:18 1.9 @@ -1,9 +1,151 @@ +*> \brief \b ZPBTF2 +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download ZPBTF2 + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE ZPBTF2( UPLO, N, KD, AB, LDAB, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER UPLO +* INTEGER INFO, KD, LDAB, N +* .. +* .. Array Arguments .. +* COMPLEX*16 AB( LDAB, * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> ZPBTF2 computes the Cholesky factorization of a complex Hermitian +*> positive definite band matrix A. +*> +*> The factorization has the form +*> A = U**H * U , if UPLO = 'U', or +*> A = L * L**H, if UPLO = 'L', +*> where U is an upper triangular matrix, U**H is the conjugate transpose +*> of U, and L is lower triangular. +*> +*> This is the unblocked version of the algorithm, calling Level 2 BLAS. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] UPLO +*> \verbatim +*> UPLO is CHARACTER*1 +*> Specifies whether the upper or lower triangular part of the +*> Hermitian matrix A is stored: +*> = 'U': Upper triangular +*> = 'L': Lower triangular +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The order of the matrix A. N >= 0. +*> \endverbatim +*> +*> \param[in] KD +*> \verbatim +*> KD is INTEGER +*> The number of super-diagonals of the matrix A if UPLO = 'U', +*> or the number of sub-diagonals if UPLO = 'L'. KD >= 0. +*> \endverbatim +*> +*> \param[in,out] AB +*> \verbatim +*> AB is COMPLEX*16 array, dimension (LDAB,N) +*> On entry, the upper or lower triangle of the Hermitian band +*> matrix A, stored in the first KD+1 rows of the array. The +*> j-th column of A is stored in the j-th column of the array AB +*> as follows: +*> if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; +*> if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd). +*> +*> On exit, if INFO = 0, the triangular factor U or L from the +*> Cholesky factorization A = U**H *U or A = L*L**H of the band +*> matrix A, in the same storage format as A. +*> \endverbatim +*> +*> \param[in] LDAB +*> \verbatim +*> LDAB is INTEGER +*> The leading dimension of the array AB. LDAB >= KD+1. +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit +*> < 0: if INFO = -k, the k-th argument had an illegal value +*> > 0: if INFO = k, the leading minor of order k is not +*> positive definite, and the factorization could not be +*> completed. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup complex16OTHERcomputational +* +*> \par Further Details: +* ===================== +*> +*> \verbatim +*> +*> The band storage scheme is illustrated by the following example, when +*> N = 6, KD = 2, and UPLO = 'U': +*> +*> On entry: On exit: +*> +*> * * a13 a24 a35 a46 * * 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 +*> +*> Similarly, if UPLO = 'L' the format of A is as follows: +*> +*> On entry: On exit: +*> +*> a11 a22 a33 a44 a55 a66 l11 l22 l33 l44 l55 l66 +*> a21 a32 a43 a54 a65 * l21 l32 l43 l54 l65 * +*> a31 a42 a53 a64 * * l31 l42 l53 l64 * * +*> +*> Array elements marked * are not used by the routine. +*> \endverbatim +*> +* ===================================================================== SUBROUTINE ZPBTF2( UPLO, N, KD, AB, LDAB, INFO ) * -* -- LAPACK routine (version 3.3.1) -- +* -- 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..-- -* -- April 2011 -- +* November 2011 * * .. Scalar Arguments .. CHARACTER UPLO @@ -13,80 +155,6 @@ COMPLEX*16 AB( LDAB, * ) * .. * -* Purpose -* ======= -* -* ZPBTF2 computes the Cholesky factorization of a complex Hermitian -* positive definite band matrix A. -* -* The factorization has the form -* A = U**H * U , if UPLO = 'U', or -* A = L * L**H, if UPLO = 'L', -* where U is an upper triangular matrix, U**H is the conjugate transpose -* of U, and L is lower triangular. -* -* This is the unblocked version of the algorithm, calling Level 2 BLAS. -* -* Arguments -* ========= -* -* UPLO (input) CHARACTER*1 -* Specifies whether the upper or lower triangular part of the -* Hermitian matrix A is stored: -* = 'U': Upper triangular -* = 'L': Lower triangular -* -* N (input) INTEGER -* The order of the matrix A. N >= 0. -* -* KD (input) INTEGER -* The number of super-diagonals of the matrix A if UPLO = 'U', -* or the number of sub-diagonals if UPLO = 'L'. KD >= 0. -* -* AB (input/output) COMPLEX*16 array, dimension (LDAB,N) -* On entry, the upper or lower triangle of the Hermitian band -* matrix A, stored in the first KD+1 rows of the array. The -* j-th column of A is stored in the j-th column of the array AB -* as follows: -* if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; -* if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd). -* -* On exit, if INFO = 0, the triangular factor U or L from the -* Cholesky factorization A = U**H *U or A = L*L**H of the band -* matrix A, in the same storage format as A. -* -* LDAB (input) INTEGER -* The leading dimension of the array AB. LDAB >= KD+1. -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -k, the k-th argument had an illegal value -* > 0: if INFO = k, the leading minor of order k is not -* positive definite, and the factorization could not be -* completed. -* -* Further Details -* =============== -* -* The band storage scheme is illustrated by the following example, when -* N = 6, KD = 2, and UPLO = 'U': -* -* On entry: On exit: -* -* * * a13 a24 a35 a46 * * 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 -* -* Similarly, if UPLO = 'L' the format of A is as follows: -* -* On entry: On exit: -* -* a11 a22 a33 a44 a55 a66 l11 l22 l33 l44 l55 l66 -* a21 a32 a43 a54 a65 * l21 l32 l43 l54 l65 * -* a31 a42 a53 a64 * * l31 l42 l53 l64 * * -* -* Array elements marked * are not used by the routine. -* * ===================================================================== * * .. Parameters ..