LAPACK  3.8.0 LAPACK: Linear Algebra PACKage

## ◆ dlag2s()

 subroutine dlag2s ( integer M, integer N, double precision, dimension( lda, * ) A, integer LDA, real, dimension( ldsa, * ) SA, integer LDSA, integer INFO )

DLAG2S converts a double precision matrix to a single precision matrix.

Purpose:
``` DLAG2S converts a DOUBLE PRECISION matrix, SA, to a SINGLE
PRECISION matrix, A.

RMAX is the overflow for the SINGLE PRECISION arithmetic
DLAG2S 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 DOUBLE PRECISION 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 REAL 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.```
Date
December 2016

Definition at line 110 of file dlag2s.f.

110 *
111 * -- LAPACK auxiliary routine (version 3.7.0) --
112 * -- LAPACK is a software package provided by Univ. of Tennessee, --
113 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
114 * December 2016
115 *
116 * .. Scalar Arguments ..
117  INTEGER info, lda, ldsa, m, n
118 * ..
119 * .. Array Arguments ..
120  REAL sa( ldsa, * )
121  DOUBLE PRECISION a( lda, * )
122 * ..
123 *
124 * =====================================================================
125 *
126 * .. Local Scalars ..
127  INTEGER i, j
128  DOUBLE PRECISION rmax
129 * ..
130 * .. External Functions ..
131  REAL slamch
132  EXTERNAL slamch
133 * ..
134 * .. Executable Statements ..
135 *
136  rmax = slamch( 'O' )
137  DO 20 j = 1, n
138  DO 10 i = 1, m
139  IF( ( a( i, j ).LT.-rmax ) .OR. ( a( i, j ).GT.rmax ) ) THEN
140  info = 1
141  GO TO 30
142  END IF
143  sa( i, j ) = a( i, j )
144  10 CONTINUE
145  20 CONTINUE
146  info = 0
147  30 CONTINUE
148  RETURN
149 *
150 * End of DLAG2S
151 *
real function slamch(CMACH)
SLAMCH
Definition: slamch.f:69
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