59 lines
1.4 KiB
FortranFixed
59 lines
1.4 KiB
FortranFixed
INTEGER FUNCTION ILADLC(M, N, A, LDA)
|
|
IMPLICIT NONE
|
|
!
|
|
! -- LAPACK auxiliary routine (version 3.1) --
|
|
! Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
|
|
! December 2007
|
|
!
|
|
! .. Scalar Arguments ..
|
|
INTEGER M, N, LDA
|
|
! ..
|
|
! .. Array Arguments ..
|
|
DOUBLE PRECISION A( LDA, * )
|
|
! ..
|
|
!
|
|
! Purpose
|
|
! =======
|
|
!
|
|
! ILADLC 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) DOUBLE PRECISION 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 ..
|
|
DOUBLE PRECISION ZERO
|
|
PARAMETER ( ZERO = 0.0D+0 )
|
|
! ..
|
|
! .. Local Scalars ..
|
|
INTEGER I, J
|
|
! ..
|
|
! .. 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
|
|
ILADLC = N
|
|
ELSE
|
|
! Now scan each column from the end, returning with the first non-zero.
|
|
DO ILADLC = N, 1, -1
|
|
DO I = 1, M
|
|
IF( A(I, ILADLC).NE.ZERO ) RETURN
|
|
END DO
|
|
END DO
|
|
END IF
|
|
RETURN
|
|
END FUNCTION
|