INTEGER FUNCTION ILACLC(M, N, A, LDA) IMPLICIT NONE ! ! -- LAPACK auxiliary routine (version 3.2) -- ! Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. ! December 2007 ! ! .. Scalar Arguments .. INTEGER M, N, LDA ! .. ! .. Array Arguments .. COMPLEX A( LDA, * ) ! .. ! ! Purpose ! ======= ! ! ILACLC 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 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 ZERO PARAMETER ( ZERO = (0.0E+0, 0.0E+0) ) ! .. ! .. Local Scalars .. INTEGER I ! .. ! .. Executable Statements .. ! ! Quick test for the common case where one corner is non-zero. IF( N.EQ.0 .OR. A(1, N).NE.ZERO .OR. A(M, N).NE.ZERO ) THEN ILACLC = N ELSE ! Now scan each column from the end, returning with the first non-zero. DO ILACLC = N, 1, -1 DO I = 1, M IF( A(I, ILACLC).NE.ZERO ) RETURN END DO END DO END IF RETURN END FUNCTION