 LAPACK 3.11.0 LAPACK: Linear Algebra PACKage
Searching...
No Matches

## ◆ 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.

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.```

Definition at line 106 of file zlag2c.f.

107*
108* -- LAPACK auxiliary routine --
109* -- LAPACK is a software package provided by Univ. of Tennessee, --
110* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
111*
112* .. Scalar Arguments ..
113 INTEGER INFO, LDA, LDSA, M, N
114* ..
115* .. Array Arguments ..
116 COMPLEX SA( LDSA, * )
117 COMPLEX*16 A( LDA, * )
118* ..
119*
120* =====================================================================
121*
122* .. Local Scalars ..
123 INTEGER I, J
124 DOUBLE PRECISION RMAX
125* ..
126* .. Intrinsic Functions ..
127 INTRINSIC dble, dimag, cmplx
128* ..
129* .. External Functions ..
130 REAL SLAMCH
131 EXTERNAL slamch
132* ..
133* .. Executable Statements ..
134*
135 rmax = slamch( 'O' )
136 DO 20 j = 1, n
137 DO 10 i = 1, m
138 IF( ( dble( a( i, j ) ).LT.-rmax ) .OR.
139 \$ ( dble( a( i, j ) ).GT.rmax ) .OR.
140 \$ ( dimag( a( i, j ) ).LT.-rmax ) .OR.
141 \$ ( dimag( a( i, j ) ).GT.rmax ) ) THEN
142 info = 1
143 GO TO 30
144 END IF
145 sa( i, j ) = cmplx( a( i, j ) )
146 10 CONTINUE
147 20 CONTINUE
148 info = 0
149 30 CONTINUE
150 RETURN
151*
152* End of ZLAG2C
153*
real function slamch(CMACH)
SLAMCH
Definition: slamch.f:68
Here is the caller graph for this function: