INTEGER FUNCTION ILAZLC( M, N, A, LDA ) IMPLICIT NONE * * -- LAPACK auxiliary routine (version 3.2.2) -- * * -- June 2010 -- * * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * * .. Scalar Arguments .. INTEGER M, N, LDA * .. * .. Array Arguments .. COMPLEX*16 A( LDA, * ) * .. * * Purpose * ======= * * ILAZLC scans A for its last non-zero column. * * Arguments * ========= * * M (input) INTEGER * The number of rows of the matrix A. * * N (input) INTEGER * The number of columns of the matrix A. * * A (input) COMPLEX*16 array, dimension (LDA,N) * The m by n matrix A. * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,M). * * ===================================================================== * * .. 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