1 | *> \brief \b SLASET |
---|
2 | * |
---|
3 | * =========== DOCUMENTATION =========== |
---|
4 | * |
---|
5 | * Online html documentation available at |
---|
6 | * http://www.netlib.org/lapack/explore-html/ |
---|
7 | * |
---|
8 | *> \htmlonly |
---|
9 | *> Download SLASET + dependencies |
---|
10 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/slaset.f"> |
---|
11 | *> [TGZ]</a> |
---|
12 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/slaset.f"> |
---|
13 | *> [ZIP]</a> |
---|
14 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/slaset.f"> |
---|
15 | *> [TXT]</a> |
---|
16 | *> \endhtmlonly |
---|
17 | * |
---|
18 | * Definition: |
---|
19 | * =========== |
---|
20 | * |
---|
21 | * SUBROUTINE SLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) |
---|
22 | * |
---|
23 | * .. Scalar Arguments .. |
---|
24 | * CHARACTER UPLO |
---|
25 | * INTEGER LDA, M, N |
---|
26 | * REAL ALPHA, BETA |
---|
27 | * .. |
---|
28 | * .. Array Arguments .. |
---|
29 | * REAL A( LDA, * ) |
---|
30 | * .. |
---|
31 | * |
---|
32 | * |
---|
33 | *> \par Purpose: |
---|
34 | * ============= |
---|
35 | *> |
---|
36 | *> \verbatim |
---|
37 | *> |
---|
38 | *> SLASET 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 REAL |
---|
71 | *> The constant to which the offdiagonal elements are to be set. |
---|
72 | *> \endverbatim |
---|
73 | *> |
---|
74 | *> \param[in] BETA |
---|
75 | *> \verbatim |
---|
76 | *> BETA is REAL |
---|
77 | *> The constant to which the diagonal elements are to be set. |
---|
78 | *> \endverbatim |
---|
79 | *> |
---|
80 | *> \param[in,out] A |
---|
81 | *> \verbatim |
---|
82 | *> A is REAL 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 2011 |
---|
107 | * |
---|
108 | *> \ingroup auxOTHERauxiliary |
---|
109 | * |
---|
110 | * ===================================================================== |
---|
111 | SUBROUTINE SLASET( UPLO, M, N, ALPHA, BETA, A, LDA ) |
---|
112 | * |
---|
113 | * -- LAPACK auxiliary routine (version 3.4.0) -- |
---|
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 2011 |
---|
117 | * |
---|
118 | * .. Scalar Arguments .. |
---|
119 | CHARACTER UPLO |
---|
120 | INTEGER LDA, M, N |
---|
121 | REAL ALPHA, BETA |
---|
122 | * .. |
---|
123 | * .. Array Arguments .. |
---|
124 | REAL 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 SLASET |
---|
183 | * |
---|
184 | END |
---|