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721 lines
20 KiB
721 lines
20 KiB
/* dlasyf.f -- translated by f2c (version 20061008). |
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You must link the resulting object file with libf2c: |
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on Microsoft Windows system, link with libf2c.lib; |
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on Linux or Unix systems, link with .../path/to/libf2c.a -lm |
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or, if you install libf2c.a in a standard place, with -lf2c -lm |
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-- in that order, at the end of the command line, as in |
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cc *.o -lf2c -lm |
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Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., |
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|
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http://www.netlib.org/f2c/libf2c.zip |
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*/ |
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|
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#include "clapack.h" |
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|
|
|
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/* Table of constant values */ |
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|
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static integer c__1 = 1; |
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static doublereal c_b8 = -1.; |
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static doublereal c_b9 = 1.; |
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|
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/* Subroutine */ int dlasyf_(char *uplo, integer *n, integer *nb, integer *kb, |
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doublereal *a, integer *lda, integer *ipiv, doublereal *w, integer * |
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ldw, integer *info) |
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{ |
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/* System generated locals */ |
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integer a_dim1, a_offset, w_dim1, w_offset, i__1, i__2, i__3, i__4, i__5; |
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doublereal d__1, d__2, d__3; |
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|
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/* Builtin functions */ |
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double sqrt(doublereal); |
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|
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/* Local variables */ |
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integer j, k; |
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doublereal t, r1, d11, d21, d22; |
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integer jb, jj, kk, jp, kp, kw, kkw, imax, jmax; |
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doublereal alpha; |
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extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, |
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integer *), dgemm_(char *, char *, integer *, integer *, integer * |
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, doublereal *, doublereal *, integer *, doublereal *, integer *, |
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doublereal *, doublereal *, integer *); |
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extern logical lsame_(char *, char *); |
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extern /* Subroutine */ int dgemv_(char *, integer *, integer *, |
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doublereal *, doublereal *, integer *, doublereal *, integer *, |
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doublereal *, doublereal *, integer *), dcopy_(integer *, |
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doublereal *, integer *, doublereal *, integer *), dswap_(integer |
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*, doublereal *, integer *, doublereal *, integer *); |
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integer kstep; |
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doublereal absakk; |
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extern integer idamax_(integer *, doublereal *, integer *); |
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doublereal colmax, rowmax; |
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|
|
|
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/* -- LAPACK routine (version 3.2) -- */ |
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/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ |
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/* November 2006 */ |
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|
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/* .. Scalar Arguments .. */ |
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/* .. */ |
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/* .. Array Arguments .. */ |
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/* .. */ |
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|
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/* Purpose */ |
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/* ======= */ |
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|
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/* DLASYF computes a partial factorization of a real symmetric matrix A */ |
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/* using the Bunch-Kaufman diagonal pivoting method. The partial */ |
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/* factorization has the form: */ |
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|
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/* A = ( I U12 ) ( A11 0 ) ( I 0 ) if UPLO = 'U', or: */ |
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/* ( 0 U22 ) ( 0 D ) ( U12' U22' ) */ |
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|
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/* A = ( L11 0 ) ( D 0 ) ( L11' L21' ) if UPLO = 'L' */ |
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/* ( L21 I ) ( 0 A22 ) ( 0 I ) */ |
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|
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/* where the order of D is at most NB. The actual order is returned in */ |
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/* the argument KB, and is either NB or NB-1, or N if N <= NB. */ |
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|
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/* DLASYF is an auxiliary routine called by DSYTRF. It uses blocked code */ |
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/* (calling Level 3 BLAS) to update the submatrix A11 (if UPLO = 'U') or */ |
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/* A22 (if UPLO = 'L'). */ |
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|
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/* Arguments */ |
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/* ========= */ |
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|
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/* UPLO (input) CHARACTER*1 */ |
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/* Specifies whether the upper or lower triangular part of the */ |
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/* symmetric matrix A is stored: */ |
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/* = 'U': Upper triangular */ |
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/* = 'L': Lower triangular */ |
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|
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/* N (input) INTEGER */ |
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/* The order of the matrix A. N >= 0. */ |
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|
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/* NB (input) INTEGER */ |
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/* The maximum number of columns of the matrix A that should be */ |
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/* factored. NB should be at least 2 to allow for 2-by-2 pivot */ |
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/* blocks. */ |
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|
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/* KB (output) INTEGER */ |
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/* The number of columns of A that were actually factored. */ |
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/* KB is either NB-1 or NB, or N if N <= NB. */ |
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|
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/* A (input/output) DOUBLE PRECISION array, dimension (LDA,N) */ |
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/* On entry, the symmetric matrix A. If UPLO = 'U', the leading */ |
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/* n-by-n upper triangular part of A contains the upper */ |
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/* triangular part of the matrix A, and the strictly lower */ |
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/* triangular part of A is not referenced. If UPLO = 'L', the */ |
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/* leading n-by-n lower triangular part of A contains the lower */ |
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/* triangular part of the matrix A, and the strictly upper */ |
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/* triangular part of A is not referenced. */ |
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/* On exit, A contains details of the partial factorization. */ |
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|
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/* LDA (input) INTEGER */ |
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/* The leading dimension of the array A. LDA >= max(1,N). */ |
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|
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/* IPIV (output) INTEGER array, dimension (N) */ |
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/* Details of the interchanges and the block structure of D. */ |
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/* If UPLO = 'U', only the last KB elements of IPIV are set; */ |
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/* if UPLO = 'L', only the first KB elements are set. */ |
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|
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/* If IPIV(k) > 0, then rows and columns k and IPIV(k) were */ |
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/* interchanged and D(k,k) is a 1-by-1 diagonal block. */ |
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/* If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0, then rows and */ |
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/* columns k-1 and -IPIV(k) were interchanged and D(k-1:k,k-1:k) */ |
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/* is a 2-by-2 diagonal block. If UPLO = 'L' and IPIV(k) = */ |
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/* IPIV(k+1) < 0, then rows and columns k+1 and -IPIV(k) were */ |
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/* interchanged and D(k:k+1,k:k+1) is a 2-by-2 diagonal block. */ |
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|
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/* W (workspace) DOUBLE PRECISION array, dimension (LDW,NB) */ |
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|
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/* LDW (input) INTEGER */ |
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/* The leading dimension of the array W. LDW >= max(1,N). */ |
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|
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/* INFO (output) INTEGER */ |
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/* = 0: successful exit */ |
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/* > 0: if INFO = k, D(k,k) is exactly zero. The factorization */ |
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/* has been completed, but the block diagonal matrix D is */ |
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/* exactly singular. */ |
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|
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/* ===================================================================== */ |
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|
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/* .. Parameters .. */ |
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/* .. */ |
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/* .. Local Scalars .. */ |
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/* .. */ |
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/* .. External Functions .. */ |
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/* .. */ |
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/* .. External Subroutines .. */ |
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/* .. */ |
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/* .. Intrinsic Functions .. */ |
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/* .. */ |
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/* .. Executable Statements .. */ |
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|
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/* Parameter adjustments */ |
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a_dim1 = *lda; |
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a_offset = 1 + a_dim1; |
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a -= a_offset; |
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--ipiv; |
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w_dim1 = *ldw; |
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w_offset = 1 + w_dim1; |
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w -= w_offset; |
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|
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/* Function Body */ |
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*info = 0; |
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|
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/* Initialize ALPHA for use in choosing pivot block size. */ |
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alpha = (sqrt(17.) + 1.) / 8.; |
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if (lsame_(uplo, "U")) { |
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|
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/* Factorize the trailing columns of A using the upper triangle */ |
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/* of A and working backwards, and compute the matrix W = U12*D */ |
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/* for use in updating A11 */ |
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|
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/* K is the main loop index, decreasing from N in steps of 1 or 2 */ |
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|
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/* KW is the column of W which corresponds to column K of A */ |
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k = *n; |
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L10: |
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kw = *nb + k - *n; |
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|
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/* Exit from loop */ |
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|
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if (k <= *n - *nb + 1 && *nb < *n || k < 1) { |
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goto L30; |
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} |
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|
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/* Copy column K of A to column KW of W and update it */ |
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dcopy_(&k, &a[k * a_dim1 + 1], &c__1, &w[kw * w_dim1 + 1], &c__1); |
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if (k < *n) { |
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i__1 = *n - k; |
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dgemv_("No transpose", &k, &i__1, &c_b8, &a[(k + 1) * a_dim1 + 1], |
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lda, &w[k + (kw + 1) * w_dim1], ldw, &c_b9, &w[kw * |
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w_dim1 + 1], &c__1); |
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} |
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kstep = 1; |
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|
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/* Determine rows and columns to be interchanged and whether */ |
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/* a 1-by-1 or 2-by-2 pivot block will be used */ |
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absakk = (d__1 = w[k + kw * w_dim1], abs(d__1)); |
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/* IMAX is the row-index of the largest off-diagonal element in */ |
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/* column K, and COLMAX is its absolute value */ |
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if (k > 1) { |
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i__1 = k - 1; |
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imax = idamax_(&i__1, &w[kw * w_dim1 + 1], &c__1); |
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colmax = (d__1 = w[imax + kw * w_dim1], abs(d__1)); |
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} else { |
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colmax = 0.; |
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} |
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if (max(absakk,colmax) == 0.) { |
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/* Column K is zero: set INFO and continue */ |
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if (*info == 0) { |
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*info = k; |
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} |
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kp = k; |
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} else { |
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if (absakk >= alpha * colmax) { |
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/* no interchange, use 1-by-1 pivot block */ |
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kp = k; |
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} else { |
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/* Copy column IMAX to column KW-1 of W and update it */ |
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dcopy_(&imax, &a[imax * a_dim1 + 1], &c__1, &w[(kw - 1) * |
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w_dim1 + 1], &c__1); |
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i__1 = k - imax; |
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dcopy_(&i__1, &a[imax + (imax + 1) * a_dim1], lda, &w[imax + |
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1 + (kw - 1) * w_dim1], &c__1); |
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if (k < *n) { |
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i__1 = *n - k; |
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dgemv_("No transpose", &k, &i__1, &c_b8, &a[(k + 1) * |
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a_dim1 + 1], lda, &w[imax + (kw + 1) * w_dim1], |
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ldw, &c_b9, &w[(kw - 1) * w_dim1 + 1], &c__1); |
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} |
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/* JMAX is the column-index of the largest off-diagonal */ |
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/* element in row IMAX, and ROWMAX is its absolute value */ |
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i__1 = k - imax; |
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jmax = imax + idamax_(&i__1, &w[imax + 1 + (kw - 1) * w_dim1], |
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&c__1); |
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rowmax = (d__1 = w[jmax + (kw - 1) * w_dim1], abs(d__1)); |
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if (imax > 1) { |
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i__1 = imax - 1; |
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jmax = idamax_(&i__1, &w[(kw - 1) * w_dim1 + 1], &c__1); |
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/* Computing MAX */ |
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d__2 = rowmax, d__3 = (d__1 = w[jmax + (kw - 1) * w_dim1], |
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abs(d__1)); |
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rowmax = max(d__2,d__3); |
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} |
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if (absakk >= alpha * colmax * (colmax / rowmax)) { |
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/* no interchange, use 1-by-1 pivot block */ |
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kp = k; |
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} else if ((d__1 = w[imax + (kw - 1) * w_dim1], abs(d__1)) >= |
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alpha * rowmax) { |
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/* interchange rows and columns K and IMAX, use 1-by-1 */ |
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/* pivot block */ |
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kp = imax; |
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/* copy column KW-1 of W to column KW */ |
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dcopy_(&k, &w[(kw - 1) * w_dim1 + 1], &c__1, &w[kw * |
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w_dim1 + 1], &c__1); |
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} else { |
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/* interchange rows and columns K-1 and IMAX, use 2-by-2 */ |
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/* pivot block */ |
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kp = imax; |
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kstep = 2; |
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} |
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} |
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kk = k - kstep + 1; |
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kkw = *nb + kk - *n; |
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/* Updated column KP is already stored in column KKW of W */ |
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if (kp != kk) { |
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/* Copy non-updated column KK to column KP */ |
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a[kp + k * a_dim1] = a[kk + k * a_dim1]; |
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i__1 = k - 1 - kp; |
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dcopy_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + (kp + |
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1) * a_dim1], lda); |
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dcopy_(&kp, &a[kk * a_dim1 + 1], &c__1, &a[kp * a_dim1 + 1], & |
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c__1); |
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|
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/* Interchange rows KK and KP in last KK columns of A and W */ |
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i__1 = *n - kk + 1; |
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dswap_(&i__1, &a[kk + kk * a_dim1], lda, &a[kp + kk * a_dim1], |
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lda); |
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i__1 = *n - kk + 1; |
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dswap_(&i__1, &w[kk + kkw * w_dim1], ldw, &w[kp + kkw * |
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w_dim1], ldw); |
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} |
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|
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if (kstep == 1) { |
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|
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/* 1-by-1 pivot block D(k): column KW of W now holds */ |
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|
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/* W(k) = U(k)*D(k) */ |
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|
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/* where U(k) is the k-th column of U */ |
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|
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/* Store U(k) in column k of A */ |
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|
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dcopy_(&k, &w[kw * w_dim1 + 1], &c__1, &a[k * a_dim1 + 1], & |
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c__1); |
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r1 = 1. / a[k + k * a_dim1]; |
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i__1 = k - 1; |
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dscal_(&i__1, &r1, &a[k * a_dim1 + 1], &c__1); |
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} else { |
|
|
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/* 2-by-2 pivot block D(k): columns KW and KW-1 of W now */ |
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/* hold */ |
|
|
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/* ( W(k-1) W(k) ) = ( U(k-1) U(k) )*D(k) */ |
|
|
|
/* where U(k) and U(k-1) are the k-th and (k-1)-th columns */ |
|
/* of U */ |
|
|
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if (k > 2) { |
|
|
|
/* Store U(k) and U(k-1) in columns k and k-1 of A */ |
|
|
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d21 = w[k - 1 + kw * w_dim1]; |
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d11 = w[k + kw * w_dim1] / d21; |
|
d22 = w[k - 1 + (kw - 1) * w_dim1] / d21; |
|
t = 1. / (d11 * d22 - 1.); |
|
d21 = t / d21; |
|
i__1 = k - 2; |
|
for (j = 1; j <= i__1; ++j) { |
|
a[j + (k - 1) * a_dim1] = d21 * (d11 * w[j + (kw - 1) |
|
* w_dim1] - w[j + kw * w_dim1]); |
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a[j + k * a_dim1] = d21 * (d22 * w[j + kw * w_dim1] - |
|
w[j + (kw - 1) * w_dim1]); |
|
/* L20: */ |
|
} |
|
} |
|
|
|
/* Copy D(k) to A */ |
|
|
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a[k - 1 + (k - 1) * a_dim1] = w[k - 1 + (kw - 1) * w_dim1]; |
|
a[k - 1 + k * a_dim1] = w[k - 1 + kw * w_dim1]; |
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a[k + k * a_dim1] = w[k + kw * w_dim1]; |
|
} |
|
} |
|
|
|
/* Store details of the interchanges in IPIV */ |
|
|
|
if (kstep == 1) { |
|
ipiv[k] = kp; |
|
} else { |
|
ipiv[k] = -kp; |
|
ipiv[k - 1] = -kp; |
|
} |
|
|
|
/* Decrease K and return to the start of the main loop */ |
|
|
|
k -= kstep; |
|
goto L10; |
|
|
|
L30: |
|
|
|
/* Update the upper triangle of A11 (= A(1:k,1:k)) as */ |
|
|
|
/* A11 := A11 - U12*D*U12' = A11 - U12*W' */ |
|
|
|
/* computing blocks of NB columns at a time */ |
|
|
|
i__1 = -(*nb); |
|
for (j = (k - 1) / *nb * *nb + 1; i__1 < 0 ? j >= 1 : j <= 1; j += |
|
i__1) { |
|
/* Computing MIN */ |
|
i__2 = *nb, i__3 = k - j + 1; |
|
jb = min(i__2,i__3); |
|
|
|
/* Update the upper triangle of the diagonal block */ |
|
|
|
i__2 = j + jb - 1; |
|
for (jj = j; jj <= i__2; ++jj) { |
|
i__3 = jj - j + 1; |
|
i__4 = *n - k; |
|
dgemv_("No transpose", &i__3, &i__4, &c_b8, &a[j + (k + 1) * |
|
a_dim1], lda, &w[jj + (kw + 1) * w_dim1], ldw, &c_b9, |
|
&a[j + jj * a_dim1], &c__1); |
|
/* L40: */ |
|
} |
|
|
|
/* Update the rectangular superdiagonal block */ |
|
|
|
i__2 = j - 1; |
|
i__3 = *n - k; |
|
dgemm_("No transpose", "Transpose", &i__2, &jb, &i__3, &c_b8, &a[( |
|
k + 1) * a_dim1 + 1], lda, &w[j + (kw + 1) * w_dim1], ldw, |
|
&c_b9, &a[j * a_dim1 + 1], lda); |
|
/* L50: */ |
|
} |
|
|
|
/* Put U12 in standard form by partially undoing the interchanges */ |
|
/* in columns k+1:n */ |
|
|
|
j = k + 1; |
|
L60: |
|
jj = j; |
|
jp = ipiv[j]; |
|
if (jp < 0) { |
|
jp = -jp; |
|
++j; |
|
} |
|
++j; |
|
if (jp != jj && j <= *n) { |
|
i__1 = *n - j + 1; |
|
dswap_(&i__1, &a[jp + j * a_dim1], lda, &a[jj + j * a_dim1], lda); |
|
} |
|
if (j <= *n) { |
|
goto L60; |
|
} |
|
|
|
/* Set KB to the number of columns factorized */ |
|
|
|
*kb = *n - k; |
|
|
|
} else { |
|
|
|
/* Factorize the leading columns of A using the lower triangle */ |
|
/* of A and working forwards, and compute the matrix W = L21*D */ |
|
/* for use in updating A22 */ |
|
|
|
/* K is the main loop index, increasing from 1 in steps of 1 or 2 */ |
|
|
|
k = 1; |
|
L70: |
|
|
|
/* Exit from loop */ |
|
|
|
if (k >= *nb && *nb < *n || k > *n) { |
|
goto L90; |
|
} |
|
|
|
/* Copy column K of A to column K of W and update it */ |
|
|
|
i__1 = *n - k + 1; |
|
dcopy_(&i__1, &a[k + k * a_dim1], &c__1, &w[k + k * w_dim1], &c__1); |
|
i__1 = *n - k + 1; |
|
i__2 = k - 1; |
|
dgemv_("No transpose", &i__1, &i__2, &c_b8, &a[k + a_dim1], lda, &w[k |
|
+ w_dim1], ldw, &c_b9, &w[k + k * w_dim1], &c__1); |
|
|
|
kstep = 1; |
|
|
|
/* Determine rows and columns to be interchanged and whether */ |
|
/* a 1-by-1 or 2-by-2 pivot block will be used */ |
|
|
|
absakk = (d__1 = w[k + k * w_dim1], abs(d__1)); |
|
|
|
/* IMAX is the row-index of the largest off-diagonal element in */ |
|
/* column K, and COLMAX is its absolute value */ |
|
|
|
if (k < *n) { |
|
i__1 = *n - k; |
|
imax = k + idamax_(&i__1, &w[k + 1 + k * w_dim1], &c__1); |
|
colmax = (d__1 = w[imax + k * w_dim1], abs(d__1)); |
|
} else { |
|
colmax = 0.; |
|
} |
|
|
|
if (max(absakk,colmax) == 0.) { |
|
|
|
/* Column K is zero: set INFO and continue */ |
|
|
|
if (*info == 0) { |
|
*info = k; |
|
} |
|
kp = k; |
|
} else { |
|
if (absakk >= alpha * colmax) { |
|
|
|
/* no interchange, use 1-by-1 pivot block */ |
|
|
|
kp = k; |
|
} else { |
|
|
|
/* Copy column IMAX to column K+1 of W and update it */ |
|
|
|
i__1 = imax - k; |
|
dcopy_(&i__1, &a[imax + k * a_dim1], lda, &w[k + (k + 1) * |
|
w_dim1], &c__1); |
|
i__1 = *n - imax + 1; |
|
dcopy_(&i__1, &a[imax + imax * a_dim1], &c__1, &w[imax + (k + |
|
1) * w_dim1], &c__1); |
|
i__1 = *n - k + 1; |
|
i__2 = k - 1; |
|
dgemv_("No transpose", &i__1, &i__2, &c_b8, &a[k + a_dim1], |
|
lda, &w[imax + w_dim1], ldw, &c_b9, &w[k + (k + 1) * |
|
w_dim1], &c__1); |
|
|
|
/* JMAX is the column-index of the largest off-diagonal */ |
|
/* element in row IMAX, and ROWMAX is its absolute value */ |
|
|
|
i__1 = imax - k; |
|
jmax = k - 1 + idamax_(&i__1, &w[k + (k + 1) * w_dim1], &c__1) |
|
; |
|
rowmax = (d__1 = w[jmax + (k + 1) * w_dim1], abs(d__1)); |
|
if (imax < *n) { |
|
i__1 = *n - imax; |
|
jmax = imax + idamax_(&i__1, &w[imax + 1 + (k + 1) * |
|
w_dim1], &c__1); |
|
/* Computing MAX */ |
|
d__2 = rowmax, d__3 = (d__1 = w[jmax + (k + 1) * w_dim1], |
|
abs(d__1)); |
|
rowmax = max(d__2,d__3); |
|
} |
|
|
|
if (absakk >= alpha * colmax * (colmax / rowmax)) { |
|
|
|
/* no interchange, use 1-by-1 pivot block */ |
|
|
|
kp = k; |
|
} else if ((d__1 = w[imax + (k + 1) * w_dim1], abs(d__1)) >= |
|
alpha * rowmax) { |
|
|
|
/* interchange rows and columns K and IMAX, use 1-by-1 */ |
|
/* pivot block */ |
|
|
|
kp = imax; |
|
|
|
/* copy column K+1 of W to column K */ |
|
|
|
i__1 = *n - k + 1; |
|
dcopy_(&i__1, &w[k + (k + 1) * w_dim1], &c__1, &w[k + k * |
|
w_dim1], &c__1); |
|
} else { |
|
|
|
/* interchange rows and columns K+1 and IMAX, use 2-by-2 */ |
|
/* pivot block */ |
|
|
|
kp = imax; |
|
kstep = 2; |
|
} |
|
} |
|
|
|
kk = k + kstep - 1; |
|
|
|
/* Updated column KP is already stored in column KK of W */ |
|
|
|
if (kp != kk) { |
|
|
|
/* Copy non-updated column KK to column KP */ |
|
|
|
a[kp + k * a_dim1] = a[kk + k * a_dim1]; |
|
i__1 = kp - k - 1; |
|
dcopy_(&i__1, &a[k + 1 + kk * a_dim1], &c__1, &a[kp + (k + 1) |
|
* a_dim1], lda); |
|
i__1 = *n - kp + 1; |
|
dcopy_(&i__1, &a[kp + kk * a_dim1], &c__1, &a[kp + kp * |
|
a_dim1], &c__1); |
|
|
|
/* Interchange rows KK and KP in first KK columns of A and W */ |
|
|
|
dswap_(&kk, &a[kk + a_dim1], lda, &a[kp + a_dim1], lda); |
|
dswap_(&kk, &w[kk + w_dim1], ldw, &w[kp + w_dim1], ldw); |
|
} |
|
|
|
if (kstep == 1) { |
|
|
|
/* 1-by-1 pivot block D(k): column k of W now holds */ |
|
|
|
/* W(k) = L(k)*D(k) */ |
|
|
|
/* where L(k) is the k-th column of L */ |
|
|
|
/* Store L(k) in column k of A */ |
|
|
|
i__1 = *n - k + 1; |
|
dcopy_(&i__1, &w[k + k * w_dim1], &c__1, &a[k + k * a_dim1], & |
|
c__1); |
|
if (k < *n) { |
|
r1 = 1. / a[k + k * a_dim1]; |
|
i__1 = *n - k; |
|
dscal_(&i__1, &r1, &a[k + 1 + k * a_dim1], &c__1); |
|
} |
|
} else { |
|
|
|
/* 2-by-2 pivot block D(k): columns k and k+1 of W now hold */ |
|
|
|
/* ( W(k) W(k+1) ) = ( L(k) L(k+1) )*D(k) */ |
|
|
|
/* where L(k) and L(k+1) are the k-th and (k+1)-th columns */ |
|
/* of L */ |
|
|
|
if (k < *n - 1) { |
|
|
|
/* Store L(k) and L(k+1) in columns k and k+1 of A */ |
|
|
|
d21 = w[k + 1 + k * w_dim1]; |
|
d11 = w[k + 1 + (k + 1) * w_dim1] / d21; |
|
d22 = w[k + k * w_dim1] / d21; |
|
t = 1. / (d11 * d22 - 1.); |
|
d21 = t / d21; |
|
i__1 = *n; |
|
for (j = k + 2; j <= i__1; ++j) { |
|
a[j + k * a_dim1] = d21 * (d11 * w[j + k * w_dim1] - |
|
w[j + (k + 1) * w_dim1]); |
|
a[j + (k + 1) * a_dim1] = d21 * (d22 * w[j + (k + 1) * |
|
w_dim1] - w[j + k * w_dim1]); |
|
/* L80: */ |
|
} |
|
} |
|
|
|
/* Copy D(k) to A */ |
|
|
|
a[k + k * a_dim1] = w[k + k * w_dim1]; |
|
a[k + 1 + k * a_dim1] = w[k + 1 + k * w_dim1]; |
|
a[k + 1 + (k + 1) * a_dim1] = w[k + 1 + (k + 1) * w_dim1]; |
|
} |
|
} |
|
|
|
/* Store details of the interchanges in IPIV */ |
|
|
|
if (kstep == 1) { |
|
ipiv[k] = kp; |
|
} else { |
|
ipiv[k] = -kp; |
|
ipiv[k + 1] = -kp; |
|
} |
|
|
|
/* Increase K and return to the start of the main loop */ |
|
|
|
k += kstep; |
|
goto L70; |
|
|
|
L90: |
|
|
|
/* Update the lower triangle of A22 (= A(k:n,k:n)) as */ |
|
|
|
/* A22 := A22 - L21*D*L21' = A22 - L21*W' */ |
|
|
|
/* computing blocks of NB columns at a time */ |
|
|
|
i__1 = *n; |
|
i__2 = *nb; |
|
for (j = k; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) { |
|
/* Computing MIN */ |
|
i__3 = *nb, i__4 = *n - j + 1; |
|
jb = min(i__3,i__4); |
|
|
|
/* Update the lower triangle of the diagonal block */ |
|
|
|
i__3 = j + jb - 1; |
|
for (jj = j; jj <= i__3; ++jj) { |
|
i__4 = j + jb - jj; |
|
i__5 = k - 1; |
|
dgemv_("No transpose", &i__4, &i__5, &c_b8, &a[jj + a_dim1], |
|
lda, &w[jj + w_dim1], ldw, &c_b9, &a[jj + jj * a_dim1] |
|
, &c__1); |
|
/* L100: */ |
|
} |
|
|
|
/* Update the rectangular subdiagonal block */ |
|
|
|
if (j + jb <= *n) { |
|
i__3 = *n - j - jb + 1; |
|
i__4 = k - 1; |
|
dgemm_("No transpose", "Transpose", &i__3, &jb, &i__4, &c_b8, |
|
&a[j + jb + a_dim1], lda, &w[j + w_dim1], ldw, &c_b9, |
|
&a[j + jb + j * a_dim1], lda); |
|
} |
|
/* L110: */ |
|
} |
|
|
|
/* Put L21 in standard form by partially undoing the interchanges */ |
|
/* in columns 1:k-1 */ |
|
|
|
j = k - 1; |
|
L120: |
|
jj = j; |
|
jp = ipiv[j]; |
|
if (jp < 0) { |
|
jp = -jp; |
|
--j; |
|
} |
|
--j; |
|
if (jp != jj && j >= 1) { |
|
dswap_(&j, &a[jp + a_dim1], lda, &a[jj + a_dim1], lda); |
|
} |
|
if (j >= 1) { |
|
goto L120; |
|
} |
|
|
|
/* Set KB to the number of columns factorized */ |
|
|
|
*kb = k - 1; |
|
|
|
} |
|
return 0; |
|
|
|
/* End of DLASYF */ |
|
|
|
} /* dlasyf_ */
|
|
|