LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
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◆ ilaclr()

integer function ilaclr ( integer  M,
integer  N,
complex, dimension( lda, * )  A,
integer  LDA 
)

ILACLR scans a matrix for its last non-zero row.

Download ILACLR + dependencies [TGZ] [ZIP] [TXT]

Purpose:
 ILACLR scans A for its last non-zero row.
Parameters
[in]M
          M is INTEGER
          The number of rows of the matrix A.
[in]N
          N is INTEGER
          The number of columns of the matrix A.
[in]A
          A is COMPLEX array, dimension (LDA,N)
          The m by n matrix A.
[in]LDA
          LDA is INTEGER
          The leading dimension of the array A. LDA >= max(1,M).
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.

Definition at line 77 of file ilaclr.f.

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 A( LDA, * )
88* ..
89*
90* =====================================================================
91*
92* .. Parameters ..
93 COMPLEX ZERO
94 parameter( zero = (0.0e+0, 0.0e+0) )
95* ..
96* .. Local Scalars ..
97 INTEGER I, J
98* ..
99* .. Executable Statements ..
100*
101* Quick test for the common case where one corner is non-zero.
102 IF( m.EQ.0 ) THEN
103 ilaclr = m
104 ELSE IF( a(m, 1).NE.zero .OR. a(m, n).NE.zero ) THEN
105 ilaclr = m
106 ELSE
107* Scan up each column tracking the last zero row seen.
108 ilaclr = 0
109 DO j = 1, n
110 i=m
111 DO WHILE((a(max(i,1),j).EQ.zero).AND.(i.GE.1))
112 i=i-1
113 ENDDO
114 ilaclr = max( ilaclr, i )
115 END DO
116 END IF
117 RETURN
integer function ilaclr(M, N, A, LDA)
ILACLR scans a matrix for its last non-zero row.
Definition: ilaclr.f:78
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