1 | *> \brief \b ILASLC |
---|
2 | * |
---|
3 | * =========== DOCUMENTATION =========== |
---|
4 | * |
---|
5 | * Online html documentation available at |
---|
6 | * http://www.netlib.org/lapack/explore-html/ |
---|
7 | * |
---|
8 | *> \htmlonly |
---|
9 | *> Download ILASLC + dependencies |
---|
10 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ilaslc.f"> |
---|
11 | *> [TGZ]</a> |
---|
12 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ilaslc.f"> |
---|
13 | *> [ZIP]</a> |
---|
14 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ilaslc.f"> |
---|
15 | *> [TXT]</a> |
---|
16 | *> \endhtmlonly |
---|
17 | * |
---|
18 | * Definition: |
---|
19 | * =========== |
---|
20 | * |
---|
21 | * INTEGER FUNCTION ILASLC( M, N, A, LDA ) |
---|
22 | * |
---|
23 | * .. Scalar Arguments .. |
---|
24 | * INTEGER M, N, LDA |
---|
25 | * .. |
---|
26 | * .. Array Arguments .. |
---|
27 | * REAL A( LDA, * ) |
---|
28 | * .. |
---|
29 | * |
---|
30 | * |
---|
31 | *> \par Purpose: |
---|
32 | * ============= |
---|
33 | *> |
---|
34 | *> \verbatim |
---|
35 | *> |
---|
36 | *> ILASLC scans A for its last non-zero column. |
---|
37 | *> \endverbatim |
---|
38 | * |
---|
39 | * Arguments: |
---|
40 | * ========== |
---|
41 | * |
---|
42 | *> \param[in] M |
---|
43 | *> \verbatim |
---|
44 | *> M is INTEGER |
---|
45 | *> The number of rows of the matrix A. |
---|
46 | *> \endverbatim |
---|
47 | *> |
---|
48 | *> \param[in] N |
---|
49 | *> \verbatim |
---|
50 | *> N is INTEGER |
---|
51 | *> The number of columns of the matrix A. |
---|
52 | *> \endverbatim |
---|
53 | *> |
---|
54 | *> \param[in] A |
---|
55 | *> \verbatim |
---|
56 | *> A is REAL array, dimension (LDA,N) |
---|
57 | *> The m by n matrix A. |
---|
58 | *> \endverbatim |
---|
59 | *> |
---|
60 | *> \param[in] LDA |
---|
61 | *> \verbatim |
---|
62 | *> LDA is INTEGER |
---|
63 | *> The leading dimension of the array A. LDA >= max(1,M). |
---|
64 | *> \endverbatim |
---|
65 | * |
---|
66 | * Authors: |
---|
67 | * ======== |
---|
68 | * |
---|
69 | *> \author Univ. of Tennessee |
---|
70 | *> \author Univ. of California Berkeley |
---|
71 | *> \author Univ. of Colorado Denver |
---|
72 | *> \author NAG Ltd. |
---|
73 | * |
---|
74 | *> \date November 2011 |
---|
75 | * |
---|
76 | *> \ingroup realOTHERauxiliary |
---|
77 | * |
---|
78 | * ===================================================================== |
---|
79 | INTEGER FUNCTION ILASLC( M, N, A, LDA ) |
---|
80 | * |
---|
81 | * -- LAPACK auxiliary routine (version 3.4.0) -- |
---|
82 | * -- LAPACK is a software package provided by Univ. of Tennessee, -- |
---|
83 | * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
---|
84 | * November 2011 |
---|
85 | * |
---|
86 | * .. Scalar Arguments .. |
---|
87 | INTEGER M, N, LDA |
---|
88 | * .. |
---|
89 | * .. Array Arguments .. |
---|
90 | REAL A( LDA, * ) |
---|
91 | * .. |
---|
92 | * |
---|
93 | * ===================================================================== |
---|
94 | * |
---|
95 | * .. Parameters .. |
---|
96 | REAL ZERO |
---|
97 | PARAMETER ( ZERO = 0.0D+0 ) |
---|
98 | * .. |
---|
99 | * .. Local Scalars .. |
---|
100 | INTEGER I |
---|
101 | * .. |
---|
102 | * .. Executable Statements .. |
---|
103 | * |
---|
104 | * Quick test for the common case where one corner is non-zero. |
---|
105 | IF( N.EQ.0 ) THEN |
---|
106 | ILASLC = N |
---|
107 | ELSE IF( A(1, N).NE.ZERO .OR. A(M, N).NE.ZERO ) THEN |
---|
108 | ILASLC = N |
---|
109 | ELSE |
---|
110 | * Now scan each column from the end, returning with the first non-zero. |
---|
111 | DO ILASLC = N, 1, -1 |
---|
112 | DO I = 1, M |
---|
113 | IF( A(I, ILASLC).NE.ZERO ) RETURN |
---|
114 | END DO |
---|
115 | END DO |
---|
116 | END IF |
---|
117 | RETURN |
---|
118 | END |
---|