forked from lijiext/lammps
119 lines
2.9 KiB
Fortran
119 lines
2.9 KiB
Fortran
*> \brief \b ILAZLC scans a matrix for its last non-zero column.
|
|
*
|
|
* =========== DOCUMENTATION ===========
|
|
*
|
|
* Online html documentation available at
|
|
* http://www.netlib.org/lapack/explore-html/
|
|
*
|
|
*> \htmlonly
|
|
*> Download ILAZLC + dependencies
|
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ilazlc.f">
|
|
*> [TGZ]</a>
|
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ilazlc.f">
|
|
*> [ZIP]</a>
|
|
*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ilazlc.f">
|
|
*> [TXT]</a>
|
|
*> \endhtmlonly
|
|
*
|
|
* Definition:
|
|
* ===========
|
|
*
|
|
* INTEGER FUNCTION ILAZLC( M, N, A, LDA )
|
|
*
|
|
* .. Scalar Arguments ..
|
|
* INTEGER M, N, LDA
|
|
* ..
|
|
* .. Array Arguments ..
|
|
* COMPLEX*16 A( LDA, * )
|
|
* ..
|
|
*
|
|
*
|
|
*> \par Purpose:
|
|
* =============
|
|
*>
|
|
*> \verbatim
|
|
*>
|
|
*> ILAZLC scans A for its last non-zero column.
|
|
*> \endverbatim
|
|
*
|
|
* Arguments:
|
|
* ==========
|
|
*
|
|
*> \param[in] M
|
|
*> \verbatim
|
|
*> M is INTEGER
|
|
*> The number of rows of the matrix A.
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[in] N
|
|
*> \verbatim
|
|
*> N is INTEGER
|
|
*> The number of columns of the matrix A.
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[in] A
|
|
*> \verbatim
|
|
*> A is COMPLEX*16 array, dimension (LDA,N)
|
|
*> The m by n matrix A.
|
|
*> \endverbatim
|
|
*>
|
|
*> \param[in] LDA
|
|
*> \verbatim
|
|
*> LDA is INTEGER
|
|
*> The leading dimension of the array A. LDA >= max(1,M).
|
|
*> \endverbatim
|
|
*
|
|
* Authors:
|
|
* ========
|
|
*
|
|
*> \author Univ. of Tennessee
|
|
*> \author Univ. of California Berkeley
|
|
*> \author Univ. of Colorado Denver
|
|
*> \author NAG Ltd.
|
|
*
|
|
*> \date September 2012
|
|
*
|
|
*> \ingroup complex16OTHERauxiliary
|
|
*
|
|
* =====================================================================
|
|
INTEGER FUNCTION ILAZLC( M, N, A, LDA )
|
|
*
|
|
* -- LAPACK auxiliary routine (version 3.4.2) --
|
|
* -- LAPACK is a software package provided by Univ. of Tennessee, --
|
|
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
|
|
* September 2012
|
|
*
|
|
* .. Scalar Arguments ..
|
|
INTEGER M, N, LDA
|
|
* ..
|
|
* .. Array Arguments ..
|
|
COMPLEX*16 A( LDA, * )
|
|
* ..
|
|
*
|
|
* =====================================================================
|
|
*
|
|
* .. Parameters ..
|
|
COMPLEX*16 ZERO
|
|
PARAMETER ( ZERO = (0.0D+0, 0.0D+0) )
|
|
* ..
|
|
* .. Local Scalars ..
|
|
INTEGER I
|
|
* ..
|
|
* .. Executable Statements ..
|
|
*
|
|
* Quick test for the common case where one corner is non-zero.
|
|
IF( N.EQ.0 ) THEN
|
|
ILAZLC = N
|
|
ELSE IF( A(1, N).NE.ZERO .OR. A(M, N).NE.ZERO ) THEN
|
|
ILAZLC = N
|
|
ELSE
|
|
* Now scan each column from the end, returning with the first non-zero.
|
|
DO ILAZLC = N, 1, -1
|
|
DO I = 1, M
|
|
IF( A(I, ILAZLC).NE.ZERO ) RETURN
|
|
END DO
|
|
END DO
|
|
END IF
|
|
RETURN
|
|
END
|