1 DOUBLE PRECISION FUNCTION DRZT01( M, N, A, AF, LDA, TAU, WORK,
2 $ LWORK )
3 *
4 * -- LAPACK test routine (version 3.1) --
5 * Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
6 * November 2006
7 *
8 * .. Scalar Arguments ..
9 INTEGER LDA, LWORK, M, N
10 * ..
11 * .. Array Arguments ..
12 DOUBLE PRECISION A( LDA, * ), AF( LDA, * ), TAU( * ),
13 $ WORK( LWORK )
14 * ..
15 *
16 * Purpose
17 * =======
18 *
19 * DRZT01 returns
20 * || A - R*Q || / ( M * eps * ||A|| )
21 * for an upper trapezoidal A that was factored with DTZRZF.
22 *
23 * Arguments
24 * =========
25 *
26 * M (input) INTEGER
27 * The number of rows of the matrices A and AF.
28 *
29 * N (input) INTEGER
30 * The number of columns of the matrices A and AF.
31 *
32 * A (input) DOUBLE PRECISION array, dimension (LDA,N)
33 * The original upper trapezoidal M by N matrix A.
34 *
35 * AF (input) DOUBLE PRECISION array, dimension (LDA,N)
36 * The output of DTZRZF for input matrix A.
37 * The lower triangle is not referenced.
38 *
39 * LDA (input) INTEGER
40 * The leading dimension of the arrays A and AF.
41 *
42 * TAU (input) DOUBLE PRECISION array, dimension (M)
43 * Details of the Householder transformations as returned by
44 * DTZRZF.
45 *
46 * WORK (workspace) DOUBLE PRECISION array, dimension (LWORK)
47 *
48 * LWORK (input) INTEGER
49 * The length of the array WORK. LWORK >= m*n + m*nb.
50 *
51 * =====================================================================
52 *
53 * .. Parameters ..
54 DOUBLE PRECISION ZERO, ONE
55 PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
56 * ..
57 * .. Local Scalars ..
58 INTEGER I, INFO, J
59 DOUBLE PRECISION NORMA
60 * ..
61 * .. Local Arrays ..
62 DOUBLE PRECISION RWORK( 1 )
63 * ..
64 * .. External Functions ..
65 DOUBLE PRECISION DLAMCH, DLANGE
66 EXTERNAL DLAMCH, DLANGE
67 * ..
68 * .. External Subroutines ..
69 EXTERNAL DAXPY, DLASET, DORMRZ, XERBLA
70 * ..
71 * .. Intrinsic Functions ..
72 INTRINSIC DBLE, MAX
73 * ..
74 * .. Executable Statements ..
75 *
76 DRZT01 = ZERO
77 *
78 IF( LWORK.LT.M*N+M ) THEN
79 CALL XERBLA( 'DRZT01', 8 )
80 RETURN
81 END IF
82 *
83 * Quick return if possible
84 *
85 IF( M.LE.0 .OR. N.LE.0 )
86 $ RETURN
87 *
88 NORMA = DLANGE( 'One-norm', M, N, A, LDA, RWORK )
89 *
90 * Copy upper triangle R
91 *
92 CALL DLASET( 'Full', M, N, ZERO, ZERO, WORK, M )
93 DO 20 J = 1, M
94 DO 10 I = 1, J
95 WORK( ( J-1 )*M+I ) = AF( I, J )
96 10 CONTINUE
97 20 CONTINUE
98 *
99 * R = R * P(1) * ... *P(m)
100 *
101 CALL DORMRZ( 'Right', 'No tranpose', M, N, M, N-M, AF, LDA, TAU,
102 $ WORK, M, WORK( M*N+1 ), LWORK-M*N, INFO )
103 *
104 * R = R - A
105 *
106 DO 30 I = 1, N
107 CALL DAXPY( M, -ONE, A( 1, I ), 1, WORK( ( I-1 )*M+1 ), 1 )
108 30 CONTINUE
109 *
110 DRZT01 = DLANGE( 'One-norm', M, N, WORK, M, RWORK )
111 *
112 DRZT01 = DRZT01 / ( DLAMCH( 'Epsilon' )*DBLE( MAX( M, N ) ) )
113 IF( NORMA.NE.ZERO )
114 $ DRZT01 = DRZT01 / NORMA
115 *
116 RETURN
117 *
118 * End of DRZT01
119 *
120 END
2 $ LWORK )
3 *
4 * -- LAPACK test routine (version 3.1) --
5 * Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
6 * November 2006
7 *
8 * .. Scalar Arguments ..
9 INTEGER LDA, LWORK, M, N
10 * ..
11 * .. Array Arguments ..
12 DOUBLE PRECISION A( LDA, * ), AF( LDA, * ), TAU( * ),
13 $ WORK( LWORK )
14 * ..
15 *
16 * Purpose
17 * =======
18 *
19 * DRZT01 returns
20 * || A - R*Q || / ( M * eps * ||A|| )
21 * for an upper trapezoidal A that was factored with DTZRZF.
22 *
23 * Arguments
24 * =========
25 *
26 * M (input) INTEGER
27 * The number of rows of the matrices A and AF.
28 *
29 * N (input) INTEGER
30 * The number of columns of the matrices A and AF.
31 *
32 * A (input) DOUBLE PRECISION array, dimension (LDA,N)
33 * The original upper trapezoidal M by N matrix A.
34 *
35 * AF (input) DOUBLE PRECISION array, dimension (LDA,N)
36 * The output of DTZRZF for input matrix A.
37 * The lower triangle is not referenced.
38 *
39 * LDA (input) INTEGER
40 * The leading dimension of the arrays A and AF.
41 *
42 * TAU (input) DOUBLE PRECISION array, dimension (M)
43 * Details of the Householder transformations as returned by
44 * DTZRZF.
45 *
46 * WORK (workspace) DOUBLE PRECISION array, dimension (LWORK)
47 *
48 * LWORK (input) INTEGER
49 * The length of the array WORK. LWORK >= m*n + m*nb.
50 *
51 * =====================================================================
52 *
53 * .. Parameters ..
54 DOUBLE PRECISION ZERO, ONE
55 PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
56 * ..
57 * .. Local Scalars ..
58 INTEGER I, INFO, J
59 DOUBLE PRECISION NORMA
60 * ..
61 * .. Local Arrays ..
62 DOUBLE PRECISION RWORK( 1 )
63 * ..
64 * .. External Functions ..
65 DOUBLE PRECISION DLAMCH, DLANGE
66 EXTERNAL DLAMCH, DLANGE
67 * ..
68 * .. External Subroutines ..
69 EXTERNAL DAXPY, DLASET, DORMRZ, XERBLA
70 * ..
71 * .. Intrinsic Functions ..
72 INTRINSIC DBLE, MAX
73 * ..
74 * .. Executable Statements ..
75 *
76 DRZT01 = ZERO
77 *
78 IF( LWORK.LT.M*N+M ) THEN
79 CALL XERBLA( 'DRZT01', 8 )
80 RETURN
81 END IF
82 *
83 * Quick return if possible
84 *
85 IF( M.LE.0 .OR. N.LE.0 )
86 $ RETURN
87 *
88 NORMA = DLANGE( 'One-norm', M, N, A, LDA, RWORK )
89 *
90 * Copy upper triangle R
91 *
92 CALL DLASET( 'Full', M, N, ZERO, ZERO, WORK, M )
93 DO 20 J = 1, M
94 DO 10 I = 1, J
95 WORK( ( J-1 )*M+I ) = AF( I, J )
96 10 CONTINUE
97 20 CONTINUE
98 *
99 * R = R * P(1) * ... *P(m)
100 *
101 CALL DORMRZ( 'Right', 'No tranpose', M, N, M, N-M, AF, LDA, TAU,
102 $ WORK, M, WORK( M*N+1 ), LWORK-M*N, INFO )
103 *
104 * R = R - A
105 *
106 DO 30 I = 1, N
107 CALL DAXPY( M, -ONE, A( 1, I ), 1, WORK( ( I-1 )*M+1 ), 1 )
108 30 CONTINUE
109 *
110 DRZT01 = DLANGE( 'One-norm', M, N, WORK, M, RWORK )
111 *
112 DRZT01 = DRZT01 / ( DLAMCH( 'Epsilon' )*DBLE( MAX( M, N ) ) )
113 IF( NORMA.NE.ZERO )
114 $ DRZT01 = DRZT01 / NORMA
115 *
116 RETURN
117 *
118 * End of DRZT01
119 *
120 END