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LAPACK
3.4.1
LAPACK: Linear Algebra PACKage
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00001 *> \brief \b SLASET 00002 * 00003 * =========== DOCUMENTATION =========== 00004 * 00005 * Online html documentation available at 00006 * http://www.netlib.org/lapack/explore-html/ 00007 * 00008 *> \htmlonly 00009 *> Download SLASET + dependencies 00010 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/slaset.f"> 00011 *> [TGZ]</a> 00012 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/slaset.f"> 00013 *> [ZIP]</a> 00014 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/slaset.f"> 00015 *> [TXT]</a> 00016 *> \endhtmlonly 00017 * 00018 * Definition: 00019 * =========== 00020 * 00021 * SUBROUTINE SLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) 00022 * 00023 * .. Scalar Arguments .. 00024 * CHARACTER UPLO 00025 * INTEGER LDA, M, N 00026 * REAL ALPHA, BETA 00027 * .. 00028 * .. Array Arguments .. 00029 * REAL A( LDA, * ) 00030 * .. 00031 * 00032 * 00033 *> \par Purpose: 00034 * ============= 00035 *> 00036 *> \verbatim 00037 *> 00038 *> SLASET initializes an m-by-n matrix A to BETA on the diagonal and 00039 *> ALPHA on the offdiagonals. 00040 *> \endverbatim 00041 * 00042 * Arguments: 00043 * ========== 00044 * 00045 *> \param[in] UPLO 00046 *> \verbatim 00047 *> UPLO is CHARACTER*1 00048 *> Specifies the part of the matrix A to be set. 00049 *> = 'U': Upper triangular part is set; the strictly lower 00050 *> triangular part of A is not changed. 00051 *> = 'L': Lower triangular part is set; the strictly upper 00052 *> triangular part of A is not changed. 00053 *> Otherwise: All of the matrix A is set. 00054 *> \endverbatim 00055 *> 00056 *> \param[in] M 00057 *> \verbatim 00058 *> M is INTEGER 00059 *> The number of rows of the matrix A. M >= 0. 00060 *> \endverbatim 00061 *> 00062 *> \param[in] N 00063 *> \verbatim 00064 *> N is INTEGER 00065 *> The number of columns of the matrix A. N >= 0. 00066 *> \endverbatim 00067 *> 00068 *> \param[in] ALPHA 00069 *> \verbatim 00070 *> ALPHA is REAL 00071 *> The constant to which the offdiagonal elements are to be set. 00072 *> \endverbatim 00073 *> 00074 *> \param[in] BETA 00075 *> \verbatim 00076 *> BETA is REAL 00077 *> The constant to which the diagonal elements are to be set. 00078 *> \endverbatim 00079 *> 00080 *> \param[in,out] A 00081 *> \verbatim 00082 *> A is REAL array, dimension (LDA,N) 00083 *> On exit, the leading m-by-n submatrix of A is set as follows: 00084 *> 00085 *> if UPLO = 'U', A(i,j) = ALPHA, 1<=i<=j-1, 1<=j<=n, 00086 *> if UPLO = 'L', A(i,j) = ALPHA, j+1<=i<=m, 1<=j<=n, 00087 *> otherwise, A(i,j) = ALPHA, 1<=i<=m, 1<=j<=n, i.ne.j, 00088 *> 00089 *> and, for all UPLO, A(i,i) = BETA, 1<=i<=min(m,n). 00090 *> \endverbatim 00091 *> 00092 *> \param[in] LDA 00093 *> \verbatim 00094 *> LDA is INTEGER 00095 *> The leading dimension of the array A. LDA >= max(1,M). 00096 *> \endverbatim 00097 * 00098 * Authors: 00099 * ======== 00100 * 00101 *> \author Univ. of Tennessee 00102 *> \author Univ. of California Berkeley 00103 *> \author Univ. of Colorado Denver 00104 *> \author NAG Ltd. 00105 * 00106 *> \date November 2011 00107 * 00108 *> \ingroup auxOTHERauxiliary 00109 * 00110 * ===================================================================== 00111 SUBROUTINE SLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) 00112 * 00113 * -- LAPACK auxiliary routine (version 3.4.0) -- 00114 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 00115 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 00116 * November 2011 00117 * 00118 * .. Scalar Arguments .. 00119 CHARACTER UPLO 00120 INTEGER LDA, M, N 00121 REAL ALPHA, BETA 00122 * .. 00123 * .. Array Arguments .. 00124 REAL A( LDA, * ) 00125 * .. 00126 * 00127 * ===================================================================== 00128 * 00129 * .. Local Scalars .. 00130 INTEGER I, J 00131 * .. 00132 * .. External Functions .. 00133 LOGICAL LSAME 00134 EXTERNAL LSAME 00135 * .. 00136 * .. Intrinsic Functions .. 00137 INTRINSIC MIN 00138 * .. 00139 * .. Executable Statements .. 00140 * 00141 IF( LSAME( UPLO, 'U' ) ) THEN 00142 * 00143 * Set the strictly upper triangular or trapezoidal part of the 00144 * array to ALPHA. 00145 * 00146 DO 20 J = 2, N 00147 DO 10 I = 1, MIN( J-1, M ) 00148 A( I, J ) = ALPHA 00149 10 CONTINUE 00150 20 CONTINUE 00151 * 00152 ELSE IF( LSAME( UPLO, 'L' ) ) THEN 00153 * 00154 * Set the strictly lower triangular or trapezoidal part of the 00155 * array to ALPHA. 00156 * 00157 DO 40 J = 1, MIN( M, N ) 00158 DO 30 I = J + 1, M 00159 A( I, J ) = ALPHA 00160 30 CONTINUE 00161 40 CONTINUE 00162 * 00163 ELSE 00164 * 00165 * Set the leading m-by-n submatrix to ALPHA. 00166 * 00167 DO 60 J = 1, N 00168 DO 50 I = 1, M 00169 A( I, J ) = ALPHA 00170 50 CONTINUE 00171 60 CONTINUE 00172 END IF 00173 * 00174 * Set the first min(M,N) diagonal elements to BETA. 00175 * 00176 DO 70 I = 1, MIN( M, N ) 00177 A( I, I ) = BETA 00178 70 CONTINUE 00179 * 00180 RETURN 00181 * 00182 * End of SLASET 00183 * 00184 END