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Annotation of rpl/lapack/lapack/dlag2s.f, revision 1.6

1.1       bertrand    1:       SUBROUTINE DLAG2S( M, N, A, LDA, SA, LDSA, INFO )
                      2: *
                      3: *  -- LAPACK PROTOTYPE auxiliary routine (version 3.1.2) --
                      4: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
                      5: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
                      6: *     August 2007
                      7: *
                      8: *     ..
                      9: *     .. Scalar Arguments ..
                     10:       INTEGER            INFO, LDA, LDSA, M, N
                     11: *     ..
                     12: *     .. Array Arguments ..
                     13:       REAL               SA( LDSA, * )
                     14:       DOUBLE PRECISION   A( LDA, * )
                     15: *     ..
                     16: *
                     17: *  Purpose
                     18: *  =======
                     19: *
                     20: *  DLAG2S converts a DOUBLE PRECISION matrix, SA, to a SINGLE
                     21: *  PRECISION matrix, A.
                     22: *
                     23: *  RMAX is the overflow for the SINGLE PRECISION arithmetic
                     24: *  DLAG2S checks that all the entries of A are between -RMAX and
                     25: *  RMAX. If not the convertion is aborted and a flag is raised.
                     26: *
                     27: *  This is an auxiliary routine so there is no argument checking.
                     28: *
                     29: *  Arguments
                     30: *  =========
                     31: *
                     32: *  M       (input) INTEGER
                     33: *          The number of lines of the matrix A.  M >= 0.
                     34: *
                     35: *  N       (input) INTEGER
                     36: *          The number of columns of the matrix A.  N >= 0.
                     37: *
                     38: *  A       (input) DOUBLE PRECISION array, dimension (LDA,N)
                     39: *          On entry, the M-by-N coefficient matrix A.
                     40: *
                     41: *  LDA     (input) INTEGER
                     42: *          The leading dimension of the array A.  LDA >= max(1,M).
                     43: *
                     44: *  SA      (output) REAL array, dimension (LDSA,N)
                     45: *          On exit, if INFO=0, the M-by-N coefficient matrix SA; if
                     46: *          INFO>0, the content of SA is unspecified.
                     47: *
                     48: *  LDSA    (input) INTEGER
                     49: *          The leading dimension of the array SA.  LDSA >= max(1,M).
                     50: *
                     51: *  INFO    (output) INTEGER
                     52: *          = 0:  successful exit.
                     53: *          = 1:  an entry of the matrix A is greater than the SINGLE
                     54: *                PRECISION overflow threshold, in this case, the content
                     55: *                of SA in exit is unspecified.
                     56: *
                     57: *  =========
                     58: *
                     59: *     .. Local Scalars ..
                     60:       INTEGER            I, J
                     61:       DOUBLE PRECISION   RMAX
                     62: *     ..
                     63: *     .. External Functions ..
                     64:       REAL               SLAMCH
                     65:       EXTERNAL           SLAMCH
                     66: *     ..
                     67: *     .. Executable Statements ..
                     68: *
                     69:       RMAX = SLAMCH( 'O' )
                     70:       DO 20 J = 1, N
                     71:          DO 10 I = 1, M
                     72:             IF( ( A( I, J ).LT.-RMAX ) .OR. ( A( I, J ).GT.RMAX ) ) THEN
                     73:                INFO = 1
                     74:                GO TO 30
                     75:             END IF
                     76:             SA( I, J ) = A( I, J )
                     77:    10    CONTINUE
                     78:    20 CONTINUE
                     79:       INFO = 0
                     80:    30 CONTINUE
                     81:       RETURN
                     82: *
                     83: *     End of DLAG2S
                     84: *
                     85:       END