diff options
| author | jason <jason@8a072113-8704-0410-8d35-dd094bca7971> | 2008-10-28 01:38:50 +0000 |
|---|---|---|
| committer | jason <jason@8a072113-8704-0410-8d35-dd094bca7971> | 2008-10-28 01:38:50 +0000 |
| commit | baba851215b44ac3b60b9248eb02bcce7eb76247 (patch) | |
| tree | 8c0f5c006875532a30d4409f5e94b0f310ff00a7 /SRC/iladlr.f | |
Move LAPACK trunk into position.
Diffstat (limited to 'SRC/iladlr.f')
| -rw-r--r-- | SRC/iladlr.f | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/SRC/iladlr.f b/SRC/iladlr.f new file mode 100644 index 00000000..94dfe051 --- /dev/null +++ b/SRC/iladlr.f @@ -0,0 +1,60 @@ + INTEGER FUNCTION ILADLR(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 +! ======= +! +! ILADLR scans A for its last non-zero row. +! +! 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( M.EQ.0 .OR. A(M, 1).NE.ZERO .OR. A(M, N).NE.ZERO ) THEN + ILADLR = M + ELSE +! Scan up each column tracking the last zero row seen. + ILADLR = 0 + DO J = 1, N + DO I = M, 1, -1 + IF( A(I, J).NE.ZERO ) EXIT + END DO + ILADLR = MAX( ILADLR, I ) + END DO + END IF + RETURN + END FUNCTION |