github.com/gonum/lapack@v0.0.0-20181123203213-e4cdc5a0bff9/internal/testdata/netlib/dlaset.f (about) 1 *> \brief \b DLASET initializes the off-diagonal elements and the diagonal elements of a matrix to given values. 2 * 3 * =========== DOCUMENTATION =========== 4 * 5 * Online html documentation available at 6 * http://www.netlib.org/lapack/explore-html/ 7 * 8 *> \htmlonly 9 *> Download DLASET + dependencies 10 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlaset.f"> 11 *> [TGZ]</a> 12 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlaset.f"> 13 *> [ZIP]</a> 14 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlaset.f"> 15 *> [TXT]</a> 16 *> \endhtmlonly 17 * 18 * Definition: 19 * =========== 20 * 21 * SUBROUTINE DLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) 22 * 23 * .. Scalar Arguments .. 24 * CHARACTER UPLO 25 * INTEGER LDA, M, N 26 * DOUBLE PRECISION ALPHA, BETA 27 * .. 28 * .. Array Arguments .. 29 * DOUBLE PRECISION A( LDA, * ) 30 * .. 31 * 32 * 33 *> \par Purpose: 34 * ============= 35 *> 36 *> \verbatim 37 *> 38 *> DLASET initializes an m-by-n matrix A to BETA on the diagonal and 39 *> ALPHA on the offdiagonals. 40 *> \endverbatim 41 * 42 * Arguments: 43 * ========== 44 * 45 *> \param[in] UPLO 46 *> \verbatim 47 *> UPLO is CHARACTER*1 48 *> Specifies the part of the matrix A to be set. 49 *> = 'U': Upper triangular part is set; the strictly lower 50 *> triangular part of A is not changed. 51 *> = 'L': Lower triangular part is set; the strictly upper 52 *> triangular part of A is not changed. 53 *> Otherwise: All of the matrix A is set. 54 *> \endverbatim 55 *> 56 *> \param[in] M 57 *> \verbatim 58 *> M is INTEGER 59 *> The number of rows of the matrix A. M >= 0. 60 *> \endverbatim 61 *> 62 *> \param[in] N 63 *> \verbatim 64 *> N is INTEGER 65 *> The number of columns of the matrix A. N >= 0. 66 *> \endverbatim 67 *> 68 *> \param[in] ALPHA 69 *> \verbatim 70 *> ALPHA is DOUBLE PRECISION 71 *> The constant to which the offdiagonal elements are to be set. 72 *> \endverbatim 73 *> 74 *> \param[in] BETA 75 *> \verbatim 76 *> BETA is DOUBLE PRECISION 77 *> The constant to which the diagonal elements are to be set. 78 *> \endverbatim 79 *> 80 *> \param[out] A 81 *> \verbatim 82 *> A is DOUBLE PRECISION array, dimension (LDA,N) 83 *> On exit, the leading m-by-n submatrix of A is set as follows: 84 *> 85 *> if UPLO = 'U', A(i,j) = ALPHA, 1<=i<=j-1, 1<=j<=n, 86 *> if UPLO = 'L', A(i,j) = ALPHA, j+1<=i<=m, 1<=j<=n, 87 *> otherwise, A(i,j) = ALPHA, 1<=i<=m, 1<=j<=n, i.ne.j, 88 *> 89 *> and, for all UPLO, A(i,i) = BETA, 1<=i<=min(m,n). 90 *> \endverbatim 91 *> 92 *> \param[in] LDA 93 *> \verbatim 94 *> LDA is INTEGER 95 *> The leading dimension of the array A. LDA >= max(1,M). 96 *> \endverbatim 97 * 98 * Authors: 99 * ======== 100 * 101 *> \author Univ. of Tennessee 102 *> \author Univ. of California Berkeley 103 *> \author Univ. of Colorado Denver 104 *> \author NAG Ltd. 105 * 106 *> \date November 2015 107 * 108 *> \ingroup auxOTHERauxiliary 109 * 110 * ===================================================================== 111 SUBROUTINE DLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) 112 * 113 * -- LAPACK auxiliary routine (version 3.6.0) -- 114 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 115 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 116 * November 2015 117 * 118 * .. Scalar Arguments .. 119 CHARACTER UPLO 120 INTEGER LDA, M, N 121 DOUBLE PRECISION ALPHA, BETA 122 * .. 123 * .. Array Arguments .. 124 DOUBLE PRECISION A( LDA, * ) 125 * .. 126 * 127 * ===================================================================== 128 * 129 * .. Local Scalars .. 130 INTEGER I, J 131 * .. 132 * .. External Functions .. 133 LOGICAL LSAME 134 EXTERNAL LSAME 135 * .. 136 * .. Intrinsic Functions .. 137 INTRINSIC MIN 138 * .. 139 * .. Executable Statements .. 140 * 141 IF( LSAME( UPLO, 'U' ) ) THEN 142 * 143 * Set the strictly upper triangular or trapezoidal part of the 144 * array to ALPHA. 145 * 146 DO 20 J = 2, N 147 DO 10 I = 1, MIN( J-1, M ) 148 A( I, J ) = ALPHA 149 10 CONTINUE 150 20 CONTINUE 151 * 152 ELSE IF( LSAME( UPLO, 'L' ) ) THEN 153 * 154 * Set the strictly lower triangular or trapezoidal part of the 155 * array to ALPHA. 156 * 157 DO 40 J = 1, MIN( M, N ) 158 DO 30 I = J + 1, M 159 A( I, J ) = ALPHA 160 30 CONTINUE 161 40 CONTINUE 162 * 163 ELSE 164 * 165 * Set the leading m-by-n submatrix to ALPHA. 166 * 167 DO 60 J = 1, N 168 DO 50 I = 1, M 169 A( I, J ) = ALPHA 170 50 CONTINUE 171 60 CONTINUE 172 END IF 173 * 174 * Set the first min(M,N) diagonal elements to BETA. 175 * 176 DO 70 I = 1, MIN( M, N ) 177 A( I, I ) = BETA 178 70 CONTINUE 179 * 180 RETURN 181 * 182 * End of DLASET 183 * 184 END