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LAPACK
3.4.1
LAPACK: Linear Algebra PACKage
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00001 *> \brief \b SLARSCL2 00002 * 00003 * =========== DOCUMENTATION =========== 00004 * 00005 * Online html documentation available at 00006 * http://www.netlib.org/lapack/explore-html/ 00007 * 00008 *> \htmlonly 00009 *> Download SLARSCL2 + dependencies 00010 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/slarscl2.f"> 00011 *> [TGZ]</a> 00012 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/slarscl2.f"> 00013 *> [ZIP]</a> 00014 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/slarscl2.f"> 00015 *> [TXT]</a> 00016 *> \endhtmlonly 00017 * 00018 * Definition: 00019 * =========== 00020 * 00021 * SUBROUTINE SLARSCL2 ( M, N, D, X, LDX ) 00022 * 00023 * .. Scalar Arguments .. 00024 * INTEGER M, N, LDX 00025 * .. 00026 * .. Array Arguments .. 00027 * REAL D( * ), X( LDX, * ) 00028 * .. 00029 * 00030 * 00031 *> \par Purpose: 00032 * ============= 00033 *> 00034 *> \verbatim 00035 *> 00036 *> SLARSCL2 performs a reciprocal diagonal scaling on an vector: 00037 *> x <-- inv(D) * x 00038 *> where the diagonal matrix D is stored as a vector. 00039 *> 00040 *> Eventually to be replaced by BLAS_sge_diag_scale in the new BLAS 00041 *> standard. 00042 *> \endverbatim 00043 * 00044 * Arguments: 00045 * ========== 00046 * 00047 *> \param[in] M 00048 *> \verbatim 00049 *> M is INTEGER 00050 *> The number of rows of D and X. M >= 0. 00051 *> \endverbatim 00052 *> 00053 *> \param[in] N 00054 *> \verbatim 00055 *> N is INTEGER 00056 *> The number of columns of D and X. N >= 0. 00057 *> \endverbatim 00058 *> 00059 *> \param[in] D 00060 *> \verbatim 00061 *> D is REAL array, length M 00062 *> Diagonal matrix D, stored as a vector of length M. 00063 *> \endverbatim 00064 *> 00065 *> \param[in,out] X 00066 *> \verbatim 00067 *> X is REAL array, dimension (LDX,N) 00068 *> On entry, the vector X to be scaled by D. 00069 *> On exit, the scaled vector. 00070 *> \endverbatim 00071 *> 00072 *> \param[in] LDX 00073 *> \verbatim 00074 *> LDX is INTEGER 00075 *> The leading dimension of the vector X. LDX >= 0. 00076 *> \endverbatim 00077 * 00078 * Authors: 00079 * ======== 00080 * 00081 *> \author Univ. of Tennessee 00082 *> \author Univ. of California Berkeley 00083 *> \author Univ. of Colorado Denver 00084 *> \author NAG Ltd. 00085 * 00086 *> \date November 2011 00087 * 00088 *> \ingroup realOTHERcomputational 00089 * 00090 * ===================================================================== 00091 SUBROUTINE SLARSCL2 ( M, N, D, X, LDX ) 00092 * 00093 * -- LAPACK computational routine (version 3.4.0) -- 00094 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 00095 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 00096 * November 2011 00097 * 00098 * .. Scalar Arguments .. 00099 INTEGER M, N, LDX 00100 * .. 00101 * .. Array Arguments .. 00102 REAL D( * ), X( LDX, * ) 00103 * .. 00104 * 00105 * ===================================================================== 00106 * 00107 * .. Local Scalars .. 00108 INTEGER I, J 00109 * .. 00110 * .. Executable Statements .. 00111 * 00112 DO J = 1, N 00113 DO I = 1, M 00114 X( I, J ) = X( I, J ) / D( I ) 00115 END DO 00116 END DO 00117 00118 RETURN 00119 END