1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
---
:name: dorgtr
:md5sum: fcaca39eb500671fa5d4d41d70cf3fb2
:category: :subroutine
:arguments:
- uplo:
:type: char
:intent: input
- n:
:type: integer
:intent: input
- a:
:type: doublereal
:intent: input/output
:dims:
- lda
- n
- lda:
:type: integer
:intent: input
- tau:
:type: doublereal
:intent: input
:dims:
- n-1
- work:
:type: doublereal
:intent: output
:dims:
- MAX(1,lwork)
- lwork:
:type: integer
:intent: input
:option: true
:default: n-1
- info:
:type: integer
:intent: output
:substitutions: {}
:fortran_help: " SUBROUTINE DORGTR( UPLO, N, A, LDA, TAU, WORK, LWORK, INFO )\n\n\
* Purpose\n\
* =======\n\
*\n\
* DORGTR generates a real orthogonal matrix Q which is defined as the\n\
* product of n-1 elementary reflectors of order N, as returned by\n\
* DSYTRD:\n\
*\n\
* if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),\n\
*\n\
* if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).\n\
*\n\n\
* Arguments\n\
* =========\n\
*\n\
* UPLO (input) CHARACTER*1\n\
* = 'U': Upper triangle of A contains elementary reflectors\n\
* from DSYTRD;\n\
* = 'L': Lower triangle of A contains elementary reflectors\n\
* from DSYTRD.\n\
*\n\
* N (input) INTEGER\n\
* The order of the matrix Q. N >= 0.\n\
*\n\
* A (input/output) DOUBLE PRECISION array, dimension (LDA,N)\n\
* On entry, the vectors which define the elementary reflectors,\n\
* as returned by DSYTRD.\n\
* On exit, the N-by-N orthogonal matrix Q.\n\
*\n\
* LDA (input) INTEGER\n\
* The leading dimension of the array A. LDA >= max(1,N).\n\
*\n\
* TAU (input) DOUBLE PRECISION array, dimension (N-1)\n\
* TAU(i) must contain the scalar factor of the elementary\n\
* reflector H(i), as returned by DSYTRD.\n\
*\n\
* WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK))\n\
* On exit, if INFO = 0, WORK(1) returns the optimal LWORK.\n\
*\n\
* LWORK (input) INTEGER\n\
* The dimension of the array WORK. LWORK >= max(1,N-1).\n\
* For optimum performance LWORK >= (N-1)*NB, where NB is\n\
* the optimal blocksize.\n\
*\n\
* If LWORK = -1, then a workspace query is assumed; the routine\n\
* only calculates the optimal size of the WORK array, returns\n\
* this value as the first entry of the WORK array, and no error\n\
* message related to LWORK is issued by XERBLA.\n\
*\n\
* INFO (output) INTEGER\n\
* = 0: successful exit\n\
* < 0: if INFO = -i, the i-th argument had an illegal value\n\
*\n\n\
* =====================================================================\n\
*\n"
|
