ilaslr()

integer function ilaslr	(	integer	M,
		integer	N,
		real, dimension( lda, * )	A,
		integer	LDA
	)

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

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Purpose:

 ILASLR 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 REAL 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.

Date

December 2016

Definition at line 80 of file ilaslr.f.

*
*  -- LAPACK auxiliary routine (version 3.7.0) --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*     December 2016
*
*     .. Scalar Arguments ..
      INTEGER            M, N, LDA
*     ..
*     .. Array Arguments ..
      REAL               A( LDA, * )
*     ..
*
*  =====================================================================
*
*     .. Parameters ..
      REAL             ZERO
      parameter( zero = 0.0e+0 )
*     ..
*     .. Local Scalars ..
      INTEGER I, J
*     ..
*     .. Executable Statements ..
*
*     Quick test for the common case where one corner is non-zero.
      IF( m.EQ.0 ) THEN
         ilaslr = m
      ELSEIF( a(m, 1).NE.zero .OR. a(m, n).NE.zero ) THEN
         ilaslr = m
      ELSE
*     Scan up each column tracking the last zero row seen.
         ilaslr = 0
         DO j = 1, n
            i=m
            DO WHILE((a(max(i,1),j).EQ.zero).AND.(i.GE.1))
               i=i-1
            ENDDO
            ilaslr = max( ilaslr, i )
         END DO
      END IF
      RETURN