From 827843bbbdb5a27019d7d679f371a3a69053c762 Mon Sep 17 00:00:00 2001 From: Gael Guennebaud Date: Wed, 12 Jun 2013 10:12:50 +0200 Subject: Complete the lapack interface to make it complete enough for suitesparse QR. --- lapack/ilazlc.f | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 lapack/ilazlc.f (limited to 'lapack/ilazlc.f') diff --git a/lapack/ilazlc.f b/lapack/ilazlc.f new file mode 100644 index 000000000..15b149022 --- /dev/null +++ b/lapack/ilazlc.f @@ -0,0 +1,118 @@ +*> \brief \b ILAZLC +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download ILAZLC + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \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 November 2011 +* +*> \ingroup complex16OTHERauxiliary +* +* ===================================================================== + INTEGER FUNCTION ILAZLC( M, N, A, LDA ) +* +* -- LAPACK auxiliary routine (version 3.4.0) -- +* -- LAPACK is a software package provided by Univ. of Tennessee, -- +* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- +* November 2011 +* +* .. 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 -- cgit v1.2.3