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 104 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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