--- rpl/lapack/lapack/dgtsv.f 2011/07/22 07:38:05 1.8 +++ rpl/lapack/lapack/dgtsv.f 2011/11/21 20:42:53 1.9 @@ -1,9 +1,136 @@ +*> \brief \b DGTSV +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download DGTSV + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE DGTSV( N, NRHS, DL, D, DU, B, LDB, INFO ) +* +* .. Scalar Arguments .. +* INTEGER INFO, LDB, N, NRHS +* .. +* .. Array Arguments .. +* DOUBLE PRECISION B( LDB, * ), D( * ), DL( * ), DU( * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> DGTSV solves the equation +*> +*> A*X = B, +*> +*> where A is an n by n tridiagonal matrix, by Gaussian elimination with +*> partial pivoting. +*> +*> Note that the equation A**T*X = B may be solved by interchanging the +*> order of the arguments DU and DL. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The order of the matrix A. N >= 0. +*> \endverbatim +*> +*> \param[in] NRHS +*> \verbatim +*> NRHS is INTEGER +*> The number of right hand sides, i.e., the number of columns +*> of the matrix B. NRHS >= 0. +*> \endverbatim +*> +*> \param[in,out] DL +*> \verbatim +*> DL is DOUBLE PRECISION array, dimension (N-1) +*> On entry, DL must contain the (n-1) sub-diagonal elements of +*> A. +*> +*> On exit, DL is overwritten by the (n-2) elements of the +*> second super-diagonal of the upper triangular matrix U from +*> the LU factorization of A, in DL(1), ..., DL(n-2). +*> \endverbatim +*> +*> \param[in,out] D +*> \verbatim +*> D is DOUBLE PRECISION array, dimension (N) +*> On entry, D must contain the diagonal elements of A. +*> +*> On exit, D is overwritten by the n diagonal elements of U. +*> \endverbatim +*> +*> \param[in,out] DU +*> \verbatim +*> DU is DOUBLE PRECISION array, dimension (N-1) +*> On entry, DU must contain the (n-1) super-diagonal elements +*> of A. +*> +*> On exit, DU is overwritten by the (n-1) elements of the first +*> super-diagonal of U. +*> \endverbatim +*> +*> \param[in,out] B +*> \verbatim +*> B is DOUBLE PRECISION array, dimension (LDB,NRHS) +*> On entry, the N by NRHS matrix of right hand side matrix B. +*> On exit, if INFO = 0, the N by NRHS solution matrix X. +*> \endverbatim +*> +*> \param[in] LDB +*> \verbatim +*> LDB is INTEGER +*> The leading dimension of the array B. LDB >= max(1,N). +*> \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, and the solution +*> has not been computed. The factorization has not been +*> completed unless i = N. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup doubleOTHERcomputational +* +* ===================================================================== SUBROUTINE DGTSV( N, NRHS, DL, D, DU, B, LDB, 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 .. INTEGER INFO, LDB, N, NRHS @@ -12,63 +139,6 @@ DOUBLE PRECISION B( LDB, * ), D( * ), DL( * ), DU( * ) * .. * -* Purpose -* ======= -* -* DGTSV solves the equation -* -* A*X = B, -* -* where A is an n by n tridiagonal matrix, by Gaussian elimination with -* partial pivoting. -* -* Note that the equation A**T*X = B may be solved by interchanging the -* order of the arguments DU and DL. -* -* Arguments -* ========= -* -* N (input) INTEGER -* The order of the matrix A. N >= 0. -* -* NRHS (input) INTEGER -* The number of right hand sides, i.e., the number of columns -* of the matrix B. NRHS >= 0. -* -* DL (input/output) DOUBLE PRECISION array, dimension (N-1) -* On entry, DL must contain the (n-1) sub-diagonal elements of -* A. -* -* On exit, DL is overwritten by the (n-2) elements of the -* second super-diagonal of the upper triangular matrix U from -* the LU factorization of A, in DL(1), ..., DL(n-2). -* -* D (input/output) DOUBLE PRECISION array, dimension (N) -* On entry, D must contain the diagonal elements of A. -* -* On exit, D is overwritten by the n diagonal elements of U. -* -* DU (input/output) DOUBLE PRECISION array, dimension (N-1) -* On entry, DU must contain the (n-1) super-diagonal elements -* of A. -* -* On exit, DU is overwritten by the (n-1) elements of the first -* super-diagonal of U. -* -* B (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS) -* On entry, the N by NRHS matrix of right hand side matrix B. -* On exit, if INFO = 0, the N by NRHS solution matrix X. -* -* LDB (input) INTEGER -* The leading dimension of the array B. LDB >= max(1,N). -* -* 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, and the solution -* has not been computed. The factorization has not been -* completed unless i = N. -* * ===================================================================== * * .. Parameters ..