--- rpl/lapack/lapack/dlacon.f 2010/08/06 15:32:25 1.4 +++ rpl/lapack/lapack/dlacon.f 2023/08/07 08:38:53 1.19 @@ -1,9 +1,121 @@ +*> \brief \b DLACON estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products. +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download DLACON + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE DLACON( N, V, X, ISGN, EST, KASE ) +* +* .. Scalar Arguments .. +* INTEGER KASE, N +* DOUBLE PRECISION EST +* .. +* .. Array Arguments .. +* INTEGER ISGN( * ) +* DOUBLE PRECISION V( * ), X( * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> DLACON estimates the 1-norm of a square, real matrix A. +*> Reverse communication is used for evaluating matrix-vector products. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The order of the matrix. N >= 1. +*> \endverbatim +*> +*> \param[out] V +*> \verbatim +*> V is DOUBLE PRECISION array, dimension (N) +*> On the final return, V = A*W, where EST = norm(V)/norm(W) +*> (W is not returned). +*> \endverbatim +*> +*> \param[in,out] X +*> \verbatim +*> X is DOUBLE PRECISION array, dimension (N) +*> On an intermediate return, X should be overwritten by +*> A * X, if KASE=1, +*> A**T * X, if KASE=2, +*> and DLACON must be re-called with all the other parameters +*> unchanged. +*> \endverbatim +*> +*> \param[out] ISGN +*> \verbatim +*> ISGN is INTEGER array, dimension (N) +*> \endverbatim +*> +*> \param[in,out] EST +*> \verbatim +*> EST is DOUBLE PRECISION +*> On entry with KASE = 1 or 2 and JUMP = 3, EST should be +*> unchanged from the previous call to DLACON. +*> On exit, EST is an estimate (a lower bound) for norm(A). +*> \endverbatim +*> +*> \param[in,out] KASE +*> \verbatim +*> KASE is INTEGER +*> On the initial call to DLACON, KASE should be 0. +*> On an intermediate return, KASE will be 1 or 2, indicating +*> whether X should be overwritten by A * X or A**T * X. +*> On the final return from DLACON, KASE will again be 0. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \ingroup doubleOTHERauxiliary +* +*> \par Contributors: +* ================== +*> +*> Nick Higham, University of Manchester. \n +*> Originally named SONEST, dated March 16, 1988. +* +*> \par References: +* ================ +*> +*> N.J. Higham, "FORTRAN codes for estimating the one-norm of +*> a real or complex matrix, with applications to condition estimation", +*> ACM Trans. Math. Soft., vol. 14, no. 4, pp. 381-396, December 1988. +*> +* ===================================================================== SUBROUTINE DLACON( N, V, X, ISGN, EST, KASE ) * -* -- LAPACK auxiliary routine (version 3.2) -- +* -- LAPACK auxiliary routine -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* November 2006 * * .. Scalar Arguments .. INTEGER KASE, N @@ -14,52 +126,6 @@ DOUBLE PRECISION V( * ), X( * ) * .. * -* Purpose -* ======= -* -* DLACON estimates the 1-norm of a square, real matrix A. -* Reverse communication is used for evaluating matrix-vector products. -* -* Arguments -* ========= -* -* N (input) INTEGER -* The order of the matrix. N >= 1. -* -* V (workspace) DOUBLE PRECISION array, dimension (N) -* On the final return, V = A*W, where EST = norm(V)/norm(W) -* (W is not returned). -* -* X (input/output) DOUBLE PRECISION array, dimension (N) -* On an intermediate return, X should be overwritten by -* A * X, if KASE=1, -* A' * X, if KASE=2, -* and DLACON must be re-called with all the other parameters -* unchanged. -* -* ISGN (workspace) INTEGER array, dimension (N) -* -* EST (input/output) DOUBLE PRECISION -* On entry with KASE = 1 or 2 and JUMP = 3, EST should be -* unchanged from the previous call to DLACON. -* On exit, EST is an estimate (a lower bound) for norm(A). -* -* KASE (input/output) INTEGER -* On the initial call to DLACON, KASE should be 0. -* On an intermediate return, KASE will be 1 or 2, indicating -* whether X should be overwritten by A * X or A' * X. -* On the final return from DLACON, KASE will again be 0. -* -* Further Details -* ======= ======= -* -* Contributed by Nick Higham, University of Manchester. -* Originally named SONEST, dated March 16, 1988. -* -* Reference: N.J. Higham, "FORTRAN codes for estimating the one-norm of -* a real or complex matrix, with applications to condition estimation", -* ACM Trans. Math. Soft., vol. 14, no. 4, pp. 381-396, December 1988. -* * ===================================================================== * * .. Parameters ..