1*> \brief \b ILASLR
2*
3*  =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6*            http://www.netlib.org/lapack/explore-html/
7*
8*> \htmlonly
9*> Download ILASLR + dependencies
10*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ilaslr.f">
11*> [TGZ]</a>
12*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ilaslr.f">
13*> [ZIP]</a>
14*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ilaslr.f">
15*> [TXT]</a>
16*> \endhtmlonly
17*
18*  Definition:
19*  ===========
20*
21*       INTEGER FUNCTION ILASLR( 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*> ILASLR scans A for its last non-zero row.
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 April 2012
75*
76*> \ingroup realOTHERauxiliary
77*
78*  =====================================================================
79      INTEGER FUNCTION ILASLR( M, N, A, LDA )
80*
81*  -- LAPACK auxiliary routine (version 3.4.1) --
82*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
83*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
84*     April 2012
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 = 0.0E+0 )
98*     ..
99*     .. Local Scalars ..
100      INTEGER I, J
101*     ..
102*     .. Executable Statements ..
103*
104*     Quick test for the common case where one corner is non-zero.
105      IF( M.EQ.0 ) THEN
106         ILASLR = M
107      ELSEIF( A(M, 1).NE.ZERO .OR. A(M, N).NE.ZERO ) THEN
108         ILASLR = M
109      ELSE
110*     Scan up each column tracking the last zero row seen.
111         ILASLR = 0
112         DO J = 1, N
113            I=M
114            DO WHILE((A(MAX(I,1),J).EQ.ZERO).AND.(I.GE.1))
115               I=I-1
116            ENDDO
117            ILASLR = MAX( ILASLR, I )
118         END DO
119      END IF
120      RETURN
121      END
122