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author | shmel1k <shmel1k@ydb.tech> | 2022-09-02 12:44:59 +0300 |
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committer | shmel1k <shmel1k@ydb.tech> | 2022-09-02 12:44:59 +0300 |
commit | 90d450f74722da7859d6f510a869f6c6908fd12f (patch) | |
tree | 538c718dedc76cdfe37ad6d01ff250dd930d9278 /contrib/libs/clapack/spoequ.c | |
parent | 01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff) | |
download | ydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz |
[] add metering mode to CLI
Diffstat (limited to 'contrib/libs/clapack/spoequ.c')
-rw-r--r-- | contrib/libs/clapack/spoequ.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/contrib/libs/clapack/spoequ.c b/contrib/libs/clapack/spoequ.c new file mode 100644 index 0000000000..9b23897125 --- /dev/null +++ b/contrib/libs/clapack/spoequ.c @@ -0,0 +1,174 @@ +/* spoequ.f -- translated by f2c (version 20061008). + You must link the resulting object file with libf2c: + on Microsoft Windows system, link with libf2c.lib; + on Linux or Unix systems, link with .../path/to/libf2c.a -lm + or, if you install libf2c.a in a standard place, with -lf2c -lm + -- in that order, at the end of the command line, as in + cc *.o -lf2c -lm + Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., + + http://www.netlib.org/f2c/libf2c.zip +*/ + +#include "f2c.h" +#include "blaswrap.h" + +/* Subroutine */ int spoequ_(integer *n, real *a, integer *lda, real *s, real + *scond, real *amax, integer *info) +{ + /* System generated locals */ + integer a_dim1, a_offset, i__1; + real r__1, r__2; + + /* Builtin functions */ + double sqrt(doublereal); + + /* Local variables */ + integer i__; + real smin; + extern /* Subroutine */ int xerbla_(char *, integer *); + + +/* -- LAPACK routine (version 3.2) -- */ +/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ +/* November 2006 */ + +/* .. Scalar Arguments .. */ +/* .. */ +/* .. Array Arguments .. */ +/* .. */ + +/* Purpose */ +/* ======= */ + +/* SPOEQU computes row and column scalings intended to equilibrate a */ +/* symmetric positive definite matrix A and reduce its condition number */ +/* (with respect to the two-norm). S contains the scale factors, */ +/* S(i) = 1/sqrt(A(i,i)), chosen so that the scaled matrix B with */ +/* elements B(i,j) = S(i)*A(i,j)*S(j) has ones on the diagonal. This */ +/* choice of S puts the condition number of B within a factor N of the */ +/* smallest possible condition number over all possible diagonal */ +/* scalings. */ + +/* Arguments */ +/* ========= */ + +/* N (input) INTEGER */ +/* The order of the matrix A. N >= 0. */ + +/* A (input) REAL array, dimension (LDA,N) */ +/* The N-by-N symmetric positive definite matrix whose scaling */ +/* factors are to be computed. Only the diagonal elements of A */ +/* are referenced. */ + +/* LDA (input) INTEGER */ +/* The leading dimension of the array A. LDA >= max(1,N). */ + +/* S (output) REAL array, dimension (N) */ +/* If INFO = 0, S contains the scale factors for A. */ + +/* SCOND (output) REAL */ +/* If INFO = 0, S contains the ratio of the smallest S(i) to */ +/* the largest S(i). If SCOND >= 0.1 and AMAX is neither too */ +/* large nor too small, it is not worth scaling by S. */ + +/* AMAX (output) REAL */ +/* Absolute value of largest matrix element. If AMAX is very */ +/* close to overflow or very close to underflow, the matrix */ +/* should be scaled. */ + +/* INFO (output) INTEGER */ +/* = 0: successful exit */ +/* < 0: if INFO = -i, the i-th argument had an illegal value */ +/* > 0: if INFO = i, the i-th diagonal element is nonpositive. */ + +/* ===================================================================== */ + +/* .. Parameters .. */ +/* .. */ +/* .. Local Scalars .. */ +/* .. */ +/* .. External Subroutines .. */ +/* .. */ +/* .. Intrinsic Functions .. */ +/* .. */ +/* .. Executable Statements .. */ + +/* Test the input parameters. */ + + /* Parameter adjustments */ + a_dim1 = *lda; + a_offset = 1 + a_dim1; + a -= a_offset; + --s; + + /* Function Body */ + *info = 0; + if (*n < 0) { + *info = -1; + } else if (*lda < max(1,*n)) { + *info = -3; + } + if (*info != 0) { + i__1 = -(*info); + xerbla_("SPOEQU", &i__1); + return 0; + } + +/* Quick return if possible */ + + if (*n == 0) { + *scond = 1.f; + *amax = 0.f; + return 0; + } + +/* Find the minimum and maximum diagonal elements. */ + + s[1] = a[a_dim1 + 1]; + smin = s[1]; + *amax = s[1]; + i__1 = *n; + for (i__ = 2; i__ <= i__1; ++i__) { + s[i__] = a[i__ + i__ * a_dim1]; +/* Computing MIN */ + r__1 = smin, r__2 = s[i__]; + smin = dmin(r__1,r__2); +/* Computing MAX */ + r__1 = *amax, r__2 = s[i__]; + *amax = dmax(r__1,r__2); +/* L10: */ + } + + if (smin <= 0.f) { + +/* Find the first non-positive diagonal element and return. */ + + i__1 = *n; + for (i__ = 1; i__ <= i__1; ++i__) { + if (s[i__] <= 0.f) { + *info = i__; + return 0; + } +/* L20: */ + } + } else { + +/* Set the scale factors to the reciprocals */ +/* of the diagonal elements. */ + + i__1 = *n; + for (i__ = 1; i__ <= i__1; ++i__) { + s[i__] = 1.f / sqrt(s[i__]); +/* L30: */ + } + +/* Compute SCOND = min(S(I)) / max(S(I)) */ + + *scond = sqrt(smin) / sqrt(*amax); + } + return 0; + +/* End of SPOEQU */ + +} /* spoequ_ */ |