zlag2c()

subroutine zlag2c	(	integer	m,
		integer	n,
		complex*16, dimension( lda, * )	a,
		integer	lda,
		complex, dimension( ldsa, * )	sa,
		integer	ldsa,
		integer	info
	)

ZLAG2C converts a complex double precision matrix to a complex single precision matrix.

Download ZLAG2C + dependencies [TGZ] [ZIP] [TXT]

Purpose:

 ZLAG2C converts a COMPLEX*16 matrix, SA, to a COMPLEX matrix, A.

 RMAX is the overflow for the SINGLE PRECISION arithmetic
 ZLAG2C checks that all the entries of A are between -RMAX and
 RMAX. If not the conversion is aborted and a flag is raised.

 This is an auxiliary routine so there is no argument checking.

Parameters

[in]	M	M is INTEGER The number of lines of the matrix A. M >= 0.
[in]	N	N is INTEGER The number of columns of the matrix A. N >= 0.
[in]	A	A is COMPLEX*16 array, dimension (LDA,N) On entry, the M-by-N coefficient matrix A.
[in]	LDA	LDA is INTEGER The leading dimension of the array A. LDA >= max(1,M).
[out]	SA	SA is COMPLEX array, dimension (LDSA,N) On exit, if INFO=0, the M-by-N coefficient matrix SA; if INFO>0, the content of SA is unspecified.
[in]	LDSA	LDSA is INTEGER The leading dimension of the array SA. LDSA >= max(1,M).
[out]	INFO	INFO is INTEGER = 0: successful exit. = 1: an entry of the matrix A is greater than the SINGLE PRECISION overflow threshold, in this case, the content of SA in exit is unspecified.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 106 of file zlag2c.f.

*
*  -- LAPACK auxiliary routine --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
*     .. Scalar Arguments ..
      INTEGER            INFO, LDA, LDSA, M, N
*     ..
*     .. Array Arguments ..
      COMPLEX            SA( LDSA, * )
      COMPLEX*16         A( LDA, * )
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      INTEGER            I, J
      DOUBLE PRECISION   RMAX
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          dble, dimag, cmplx
*     ..
*     .. External Functions ..
      REAL               SLAMCH
      EXTERNAL           slamch
*     ..
*     .. Executable Statements ..
*
      rmax = slamch( 'O' )
      DO 20 j = 1, n
         DO 10 i = 1, m
            IF( ( dble( a( i, j ) ).LT.-rmax ) .OR.
     $          ( dble( a( i, j ) ).GT.rmax ) .OR.
     $          ( dimag( a( i, j ) ).LT.-rmax ) .OR.
     $          ( dimag( a( i, j ) ).GT.rmax ) ) THEN
               info = 1
               GO TO 30
            END IF
            sa( i, j ) = cmplx( a( i, j ) )
   10    CONTINUE
   20 CONTINUE
      info = 0
   30 CONTINUE
      RETURN
*
*     End of ZLAG2C
*

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