LAPACK 3.12.0 LAPACK: Linear Algebra PACKage
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ilazlc.f
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1*> \brief \b ILAZLC scans a matrix for its last non-zero column.
2*
3* =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6* http://www.netlib.org/lapack/explore-html/
7*
8*> \htmlonly
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11*> [TGZ]</a>
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13*> [ZIP]</a>
14*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ilazlc.f">
15*> [TXT]</a>
16*> \endhtmlonly
17*
18* Definition:
19* ===========
20*
21* INTEGER FUNCTION ILAZLC( M, N, A, LDA )
22*
23* .. Scalar Arguments ..
24* INTEGER M, N, LDA
25* ..
26* .. Array Arguments ..
27* COMPLEX*16 A( LDA, * )
28* ..
29*
30*
31*> \par Purpose:
32* =============
33*>
34*> \verbatim
35*>
36*> ILAZLC 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 COMPLEX*16 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*> \ingroup ilalc
75*
76* =====================================================================
77 INTEGER FUNCTION ilazlc( M, N, A, LDA )
78*
79* -- LAPACK auxiliary routine --
80* -- LAPACK is a software package provided by Univ. of Tennessee, --
81* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
82*
83* .. Scalar Arguments ..
84 INTEGER m, n, lda
85* ..
86* .. Array Arguments ..
87 COMPLEX*16 a( lda, * )
88* ..
89*
90* =====================================================================
91*
92* .. Parameters ..
93 COMPLEX*16 zero
94 parameter( zero = (0.0d+0, 0.0d+0) )
95* ..
96* .. Local Scalars ..
97 INTEGER i
98* ..
99* .. Executable Statements ..
100*
101* Quick test for the common case where one corner is non-zero.
102 IF( n.EQ.0 ) THEN
103 ilazlc = n
104 ELSE IF( a(1, n).NE.zero .OR. a(m, n).NE.zero ) THEN
105 ilazlc = n
106 ELSE
107* Now scan each column from the end, returning with the first non-zero.
108 DO ilazlc = n, 1, -1
109 DO i = 1, m
110 IF( a(i, ilazlc).NE.zero ) RETURN
111 END DO
112 END DO
113 END IF
114 RETURN
115 END
integer function ilazlc(m, n, a, lda)
ILAZLC scans a matrix for its last non-zero column.
Definition ilazlc.f:78