| 1 | *> \brief \b ILAZLR
|
|---|
| 2 | *
|
|---|
| 3 | * =========== DOCUMENTATION ===========
|
|---|
| 4 | *
|
|---|
| 5 | * Online html documentation available at
|
|---|
| 6 | * http://www.netlib.org/lapack/explore-html/
|
|---|
| 7 | *
|
|---|
| 8 | *> \htmlonly
|
|---|
| 9 | *> Download ILAZLR + dependencies
|
|---|
| 10 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ilazlr.f">
|
|---|
| 11 | *> [TGZ]</a>
|
|---|
| 12 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ilazlr.f">
|
|---|
| 13 | *> [ZIP]</a>
|
|---|
| 14 | *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ilazlr.f">
|
|---|
| 15 | *> [TXT]</a>
|
|---|
| 16 | *> \endhtmlonly
|
|---|
| 17 | *
|
|---|
| 18 | * Definition:
|
|---|
| 19 | * ===========
|
|---|
| 20 | *
|
|---|
| 21 | * INTEGER FUNCTION ILAZLR( 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 | *> ILAZLR 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 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 | *> \date April 2012
|
|---|
| 75 | *
|
|---|
| 76 | *> \ingroup complex16OTHERauxiliary
|
|---|
| 77 | *
|
|---|
| 78 | * =====================================================================
|
|---|
| 79 | INTEGER FUNCTION ILAZLR( 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 | COMPLEX*16 A( LDA, * )
|
|---|
| 91 | * ..
|
|---|
| 92 | *
|
|---|
| 93 | * =====================================================================
|
|---|
| 94 | *
|
|---|
| 95 | * .. Parameters ..
|
|---|
| 96 | COMPLEX*16 ZERO
|
|---|
| 97 | PARAMETER ( ZERO = (0.0D+0, 0.0D+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 | ILAZLR = M
|
|---|
| 107 | ELSE IF( A(M, 1).NE.ZERO .OR. A(M, N).NE.ZERO ) THEN
|
|---|
| 108 | ILAZLR = M
|
|---|
| 109 | ELSE
|
|---|
| 110 | * Scan up each column tracking the last zero row seen.
|
|---|
| 111 | ILAZLR = 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 | ILAZLR = MAX( ILAZLR, I )
|
|---|
| 118 | END DO
|
|---|
| 119 | END IF
|
|---|
| 120 | RETURN
|
|---|
| 121 | END
|
|---|
