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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/ssytd2.c | |
parent | 01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff) | |
download | ydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz |
[] add metering mode to CLI
Diffstat (limited to 'contrib/libs/clapack/ssytd2.c')
-rw-r--r-- | contrib/libs/clapack/ssytd2.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/contrib/libs/clapack/ssytd2.c b/contrib/libs/clapack/ssytd2.c new file mode 100644 index 0000000000..f2026353f6 --- /dev/null +++ b/contrib/libs/clapack/ssytd2.c @@ -0,0 +1,302 @@ +/* ssytd2.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" + +/* Table of constant values */ + +static integer c__1 = 1; +static real c_b8 = 0.f; +static real c_b14 = -1.f; + +/* Subroutine */ int ssytd2_(char *uplo, integer *n, real *a, integer *lda, + real *d__, real *e, real *tau, integer *info) +{ + /* System generated locals */ + integer a_dim1, a_offset, i__1, i__2, i__3; + + /* Local variables */ + integer i__; + real taui; + extern doublereal sdot_(integer *, real *, integer *, real *, integer *); + extern /* Subroutine */ int ssyr2_(char *, integer *, real *, real *, + integer *, real *, integer *, real *, integer *); + real alpha; + extern logical lsame_(char *, char *); + logical upper; + extern /* Subroutine */ int saxpy_(integer *, real *, real *, integer *, + real *, integer *), ssymv_(char *, integer *, real *, real *, + integer *, real *, integer *, real *, real *, integer *), + xerbla_(char *, integer *), slarfg_(integer *, real *, + real *, integer *, real *); + + +/* -- LAPACK routine (version 3.2) -- */ +/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ +/* November 2006 */ + +/* .. Scalar Arguments .. */ +/* .. */ +/* .. Array Arguments .. */ +/* .. */ + +/* Purpose */ +/* ======= */ + +/* SSYTD2 reduces a real symmetric matrix A to symmetric tridiagonal */ +/* form T by an orthogonal similarity transformation: Q' * A * Q = T. */ + +/* Arguments */ +/* ========= */ + +/* UPLO (input) CHARACTER*1 */ +/* Specifies whether the upper or lower triangular part of the */ +/* symmetric matrix A is stored: */ +/* = 'U': Upper triangular */ +/* = 'L': Lower triangular */ + +/* N (input) INTEGER */ +/* The order of the matrix A. N >= 0. */ + +/* A (input/output) REAL array, dimension (LDA,N) */ +/* On entry, the symmetric matrix A. If UPLO = 'U', the leading */ +/* n-by-n upper triangular part of A contains the upper */ +/* triangular part of the matrix A, and the strictly lower */ +/* triangular part of A is not referenced. If UPLO = 'L', the */ +/* leading n-by-n lower triangular part of A contains the lower */ +/* triangular part of the matrix A, and the strictly upper */ +/* triangular part of A is not referenced. */ +/* On exit, if UPLO = 'U', the diagonal and first superdiagonal */ +/* of A are overwritten by the corresponding elements of the */ +/* tridiagonal matrix T, and the elements above the first */ +/* superdiagonal, with the array TAU, represent the orthogonal */ +/* matrix Q as a product of elementary reflectors; if UPLO */ +/* = 'L', the diagonal and first subdiagonal of A are over- */ +/* written by the corresponding elements of the tridiagonal */ +/* matrix T, and the elements below the first subdiagonal, with */ +/* the array TAU, represent the orthogonal matrix Q as a product */ +/* of elementary reflectors. See Further Details. */ + +/* LDA (input) INTEGER */ +/* The leading dimension of the array A. LDA >= max(1,N). */ + +/* D (output) REAL array, dimension (N) */ +/* The diagonal elements of the tridiagonal matrix T: */ +/* D(i) = A(i,i). */ + +/* E (output) REAL array, dimension (N-1) */ +/* The off-diagonal elements of the tridiagonal matrix T: */ +/* E(i) = A(i,i+1) if UPLO = 'U', E(i) = A(i+1,i) if UPLO = 'L'. */ + +/* TAU (output) REAL array, dimension (N-1) */ +/* The scalar factors of the elementary reflectors (see Further */ +/* Details). */ + +/* INFO (output) INTEGER */ +/* = 0: successful exit */ +/* < 0: if INFO = -i, the i-th argument had an illegal value. */ + +/* Further Details */ +/* =============== */ + +/* If UPLO = 'U', the matrix Q is represented as a product of elementary */ +/* reflectors */ + +/* Q = H(n-1) . . . H(2) H(1). */ + +/* Each H(i) has the form */ + +/* H(i) = I - tau * v * v' */ + +/* where tau is a real scalar, and v is a real vector with */ +/* v(i+1:n) = 0 and v(i) = 1; v(1:i-1) is stored on exit in */ +/* A(1:i-1,i+1), and tau in TAU(i). */ + +/* If UPLO = 'L', the matrix Q is represented as a product of elementary */ +/* reflectors */ + +/* Q = H(1) H(2) . . . H(n-1). */ + +/* Each H(i) has the form */ + +/* H(i) = I - tau * v * v' */ + +/* where tau is a real scalar, and v is a real vector with */ +/* v(1:i) = 0 and v(i+1) = 1; v(i+2:n) is stored on exit in A(i+2:n,i), */ +/* and tau in TAU(i). */ + +/* The contents of A on exit are illustrated by the following examples */ +/* with n = 5: */ + +/* if UPLO = 'U': if UPLO = 'L': */ + +/* ( d e v2 v3 v4 ) ( d ) */ +/* ( d e v3 v4 ) ( e d ) */ +/* ( d e v4 ) ( v1 e d ) */ +/* ( d e ) ( v1 v2 e d ) */ +/* ( d ) ( v1 v2 v3 e d ) */ + +/* where d and e denote diagonal and off-diagonal elements of T, and vi */ +/* denotes an element of the vector defining H(i). */ + +/* ===================================================================== */ + +/* .. Parameters .. */ +/* .. */ +/* .. Local Scalars .. */ +/* .. */ +/* .. External Subroutines .. */ +/* .. */ +/* .. External Functions .. */ +/* .. */ +/* .. Intrinsic Functions .. */ +/* .. */ +/* .. Executable Statements .. */ + +/* Test the input parameters */ + + /* Parameter adjustments */ + a_dim1 = *lda; + a_offset = 1 + a_dim1; + a -= a_offset; + --d__; + --e; + --tau; + + /* Function Body */ + *info = 0; + upper = lsame_(uplo, "U"); + if (! upper && ! lsame_(uplo, "L")) { + *info = -1; + } else if (*n < 0) { + *info = -2; + } else if (*lda < max(1,*n)) { + *info = -4; + } + if (*info != 0) { + i__1 = -(*info); + xerbla_("SSYTD2", &i__1); + return 0; + } + +/* Quick return if possible */ + + if (*n <= 0) { + return 0; + } + + if (upper) { + +/* Reduce the upper triangle of A */ + + for (i__ = *n - 1; i__ >= 1; --i__) { + +/* Generate elementary reflector H(i) = I - tau * v * v' */ +/* to annihilate A(1:i-1,i+1) */ + + slarfg_(&i__, &a[i__ + (i__ + 1) * a_dim1], &a[(i__ + 1) * a_dim1 + + 1], &c__1, &taui); + e[i__] = a[i__ + (i__ + 1) * a_dim1]; + + if (taui != 0.f) { + +/* Apply H(i) from both sides to A(1:i,1:i) */ + + a[i__ + (i__ + 1) * a_dim1] = 1.f; + +/* Compute x := tau * A * v storing x in TAU(1:i) */ + + ssymv_(uplo, &i__, &taui, &a[a_offset], lda, &a[(i__ + 1) * + a_dim1 + 1], &c__1, &c_b8, &tau[1], &c__1); + +/* Compute w := x - 1/2 * tau * (x'*v) * v */ + + alpha = taui * -.5f * sdot_(&i__, &tau[1], &c__1, &a[(i__ + 1) + * a_dim1 + 1], &c__1); + saxpy_(&i__, &alpha, &a[(i__ + 1) * a_dim1 + 1], &c__1, &tau[ + 1], &c__1); + +/* Apply the transformation as a rank-2 update: */ +/* A := A - v * w' - w * v' */ + + ssyr2_(uplo, &i__, &c_b14, &a[(i__ + 1) * a_dim1 + 1], &c__1, + &tau[1], &c__1, &a[a_offset], lda); + + a[i__ + (i__ + 1) * a_dim1] = e[i__]; + } + d__[i__ + 1] = a[i__ + 1 + (i__ + 1) * a_dim1]; + tau[i__] = taui; +/* L10: */ + } + d__[1] = a[a_dim1 + 1]; + } else { + +/* Reduce the lower triangle of A */ + + i__1 = *n - 1; + for (i__ = 1; i__ <= i__1; ++i__) { + +/* Generate elementary reflector H(i) = I - tau * v * v' */ +/* to annihilate A(i+2:n,i) */ + + i__2 = *n - i__; +/* Computing MIN */ + i__3 = i__ + 2; + slarfg_(&i__2, &a[i__ + 1 + i__ * a_dim1], &a[min(i__3, *n)+ i__ * + a_dim1], &c__1, &taui); + e[i__] = a[i__ + 1 + i__ * a_dim1]; + + if (taui != 0.f) { + +/* Apply H(i) from both sides to A(i+1:n,i+1:n) */ + + a[i__ + 1 + i__ * a_dim1] = 1.f; + +/* Compute x := tau * A * v storing y in TAU(i:n-1) */ + + i__2 = *n - i__; + ssymv_(uplo, &i__2, &taui, &a[i__ + 1 + (i__ + 1) * a_dim1], + lda, &a[i__ + 1 + i__ * a_dim1], &c__1, &c_b8, &tau[ + i__], &c__1); + +/* Compute w := x - 1/2 * tau * (x'*v) * v */ + + i__2 = *n - i__; + alpha = taui * -.5f * sdot_(&i__2, &tau[i__], &c__1, &a[i__ + + 1 + i__ * a_dim1], &c__1); + i__2 = *n - i__; + saxpy_(&i__2, &alpha, &a[i__ + 1 + i__ * a_dim1], &c__1, &tau[ + i__], &c__1); + +/* Apply the transformation as a rank-2 update: */ +/* A := A - v * w' - w * v' */ + + i__2 = *n - i__; + ssyr2_(uplo, &i__2, &c_b14, &a[i__ + 1 + i__ * a_dim1], &c__1, + &tau[i__], &c__1, &a[i__ + 1 + (i__ + 1) * a_dim1], + lda); + + a[i__ + 1 + i__ * a_dim1] = e[i__]; + } + d__[i__] = a[i__ + i__ * a_dim1]; + tau[i__] = taui; +/* L20: */ + } + d__[*n] = a[*n + *n * a_dim1]; + } + + return 0; + +/* End of SSYTD2 */ + +} /* ssytd2_ */ |