SUBROUTINE DLAG2S( M, N, A, LDA, SA, LDSA, INFO) * * -- LAPACK PROTOTYPE auxiliary routine (version 3.1.1) -- * Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. * January 2007 * * .. * .. WARNING: PROTOTYPE .. * This is an LAPACK PROTOTYPE routine which means that the * interface of this routine is likely to be changed in the future * based on community feedback. * * .. Scalar Arguments .. INTEGER INFO,LDA,LDSA,M,N * .. * .. Array Arguments .. REAL SA(LDSA,*) DOUBLE PRECISION A(LDA,*) * .. * * 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 convertion is aborted and a flag is raised. * * This is a helper routine so there is no argument checking. * * Arguments * ========= * * M (input) INTEGER * The number of lines of the matrix A. M >= 0. * * N (input) INTEGER * The number of columns of the matrix A. N >= 0. * * A (input) DOUBLE PRECISION array, dimension (LDA,N) * On entry, the M-by-N coefficient matrix A. * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,M). * * SA (output) REAL array, dimension (LDSA,N) * On exit, if INFO=0, the M-by-N coefficient matrix SA. * * LDSA (input) INTEGER * The leading dimension of the array SA. LDSA >= max(1,M). * * INFO (output) INTEGER * = 0: successful exit * > 0: if INFO = k, the (i,j) entry of the matrix A has * overflowed when moving from DOUBLE PRECISION to SINGLE * k is given by k = (i-1)*LDA+j * * ========= * * .. Local Scalars .. INTEGER I,J DOUBLE PRECISION RMAX * .. * .. External Functions .. REAL SLAMCH EXTERNAL SLAMCH * .. * .. Executable Statements .. * RMAX = SLAMCH('O') DO 20 J = 1,N DO 30 I = 1,M IF ((A(I,J).LT.-RMAX) .OR. (A(I,J).GT.RMAX)) THEN INFO = (I-1)*LDA + J GO TO 10 END IF SA(I,J) = A(I,J) 30 CONTINUE 20 CONTINUE 10 CONTINUE RETURN * * End of DLAG2S * END