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LAPACK 3.3.1
Linear Algebra PACKage
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LAPACK 3.3.1
Linear Algebra PACKage
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00001 SUBROUTINE DLAG2S( M, N, A, LDA, SA, LDSA, INFO ) 00002 * 00003 * -- LAPACK PROTOTYPE auxiliary routine (version 3.3.1) -- 00004 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 00005 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 00006 * -- April 2011 -- 00007 * 00008 * .. 00009 * .. Scalar Arguments .. 00010 INTEGER INFO, LDA, LDSA, M, N 00011 * .. 00012 * .. Array Arguments .. 00013 REAL SA( LDSA, * ) 00014 DOUBLE PRECISION A( LDA, * ) 00015 * .. 00016 * 00017 * Purpose 00018 * ======= 00019 * 00020 * DLAG2S converts a DOUBLE PRECISION matrix, SA, to a SINGLE 00021 * PRECISION matrix, A. 00022 * 00023 * RMAX is the overflow for the SINGLE PRECISION arithmetic 00024 * DLAG2S checks that all the entries of A are between -RMAX and 00025 * RMAX. If not the convertion is aborted and a flag is raised. 00026 * 00027 * This is an auxiliary routine so there is no argument checking. 00028 * 00029 * Arguments 00030 * ========= 00031 * 00032 * M (input) INTEGER 00033 * The number of lines of the matrix A. M >= 0. 00034 * 00035 * N (input) INTEGER 00036 * The number of columns of the matrix A. N >= 0. 00037 * 00038 * A (input) DOUBLE PRECISION array, dimension (LDA,N) 00039 * On entry, the M-by-N coefficient matrix A. 00040 * 00041 * LDA (input) INTEGER 00042 * The leading dimension of the array A. LDA >= max(1,M). 00043 * 00044 * SA (output) REAL array, dimension (LDSA,N) 00045 * On exit, if INFO=0, the M-by-N coefficient matrix SA; if 00046 * INFO>0, the content of SA is unspecified. 00047 * 00048 * LDSA (input) INTEGER 00049 * The leading dimension of the array SA. LDSA >= max(1,M). 00050 * 00051 * INFO (output) INTEGER 00052 * = 0: successful exit. 00053 * = 1: an entry of the matrix A is greater than the SINGLE 00054 * PRECISION overflow threshold, in this case, the content 00055 * of SA in exit is unspecified. 00056 * 00057 * ===================================================================== 00058 * 00059 * .. Local Scalars .. 00060 INTEGER I, J 00061 DOUBLE PRECISION RMAX 00062 * .. 00063 * .. External Functions .. 00064 REAL SLAMCH 00065 EXTERNAL SLAMCH 00066 * .. 00067 * .. Executable Statements .. 00068 * 00069 RMAX = SLAMCH( 'O' ) 00070 DO 20 J = 1, N 00071 DO 10 I = 1, M 00072 IF( ( A( I, J ).LT.-RMAX ) .OR. ( A( I, J ).GT.RMAX ) ) THEN 00073 INFO = 1 00074 GO TO 30 00075 END IF 00076 SA( I, J ) = A( I, J ) 00077 10 CONTINUE 00078 20 CONTINUE 00079 INFO = 0 00080 30 CONTINUE 00081 RETURN 00082 * 00083 * End of DLAG2S 00084 * 00085 END
1.7.3 
