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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/zhetf2.c | |
parent | 01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff) | |
download | ydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz |
[] add metering mode to CLI
Diffstat (limited to 'contrib/libs/clapack/zhetf2.c')
-rw-r--r-- | contrib/libs/clapack/zhetf2.c | 802 |
1 files changed, 802 insertions, 0 deletions
diff --git a/contrib/libs/clapack/zhetf2.c b/contrib/libs/clapack/zhetf2.c new file mode 100644 index 0000000000..24a5289440 --- /dev/null +++ b/contrib/libs/clapack/zhetf2.c @@ -0,0 +1,802 @@ +/* zhetf2.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; + +/* Subroutine */ int zhetf2_(char *uplo, integer *n, doublecomplex *a, + integer *lda, integer *ipiv, integer *info) +{ + /* System generated locals */ + integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5, i__6; + doublereal d__1, d__2, d__3, d__4; + doublecomplex z__1, z__2, z__3, z__4, z__5, z__6; + + /* Builtin functions */ + double sqrt(doublereal), d_imag(doublecomplex *); + void d_cnjg(doublecomplex *, doublecomplex *); + + /* Local variables */ + doublereal d__; + integer i__, j, k; + doublecomplex t; + doublereal r1, d11; + doublecomplex d12; + doublereal d22; + doublecomplex d21; + integer kk, kp; + doublecomplex wk; + doublereal tt; + doublecomplex wkm1, wkp1; + integer imax, jmax; + extern /* Subroutine */ int zher_(char *, integer *, doublereal *, + doublecomplex *, integer *, doublecomplex *, integer *); + doublereal alpha; + extern logical lsame_(char *, char *); + integer kstep; + logical upper; + extern /* Subroutine */ int zswap_(integer *, doublecomplex *, integer *, + doublecomplex *, integer *); + extern doublereal dlapy2_(doublereal *, doublereal *); + doublereal absakk; + extern logical disnan_(doublereal *); + extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_( + integer *, doublereal *, doublecomplex *, integer *); + doublereal colmax; + extern integer izamax_(integer *, doublecomplex *, integer *); + doublereal rowmax; + + +/* -- LAPACK routine (version 3.2) -- */ +/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ +/* November 2006 */ + +/* .. Scalar Arguments .. */ +/* .. */ +/* .. Array Arguments .. */ +/* .. */ + +/* Purpose */ +/* ======= */ + +/* ZHETF2 computes the factorization of a complex Hermitian matrix A */ +/* using the Bunch-Kaufman diagonal pivoting method: */ + +/* A = U*D*U' or A = L*D*L' */ + +/* where U (or L) is a product of permutation and unit upper (lower) */ +/* triangular matrices, U' is the conjugate transpose of U, and D is */ +/* Hermitian and block diagonal with 1-by-1 and 2-by-2 diagonal blocks. */ + +/* This is the unblocked version of the algorithm, calling Level 2 BLAS. */ + +/* Arguments */ +/* ========= */ + +/* UPLO (input) CHARACTER*1 */ +/* Specifies whether the upper or lower triangular part of the */ +/* Hermitian matrix A is stored: */ +/* = 'U': Upper triangular */ +/* = 'L': Lower triangular */ + +/* N (input) INTEGER */ +/* The order of the matrix A. N >= 0. */ + +/* A (input/output) COMPLEX*16 array, dimension (LDA,N) */ +/* On entry, the Hermitian 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, the block diagonal matrix D and the multipliers used */ +/* to obtain the factor U or L (see below for further details). */ + +/* LDA (input) INTEGER */ +/* The leading dimension of the array A. LDA >= max(1,N). */ + +/* IPIV (output) INTEGER array, dimension (N) */ +/* Details of the interchanges and the block structure of D. */ +/* If IPIV(k) > 0, then rows and columns k and IPIV(k) were */ +/* interchanged and D(k,k) is a 1-by-1 diagonal block. */ +/* If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0, then rows and */ +/* columns k-1 and -IPIV(k) were interchanged and D(k-1:k,k-1:k) */ +/* is a 2-by-2 diagonal block. If UPLO = 'L' and IPIV(k) = */ +/* IPIV(k+1) < 0, then rows and columns k+1 and -IPIV(k) were */ +/* interchanged and D(k:k+1,k:k+1) is a 2-by-2 diagonal block. */ + +/* INFO (output) INTEGER */ +/* = 0: successful exit */ +/* < 0: if INFO = -k, the k-th argument had an illegal value */ +/* > 0: if INFO = k, D(k,k) is exactly zero. The factorization */ +/* has been completed, but the block diagonal matrix D is */ +/* exactly singular, and division by zero will occur if it */ +/* is used to solve a system of equations. */ + +/* Further Details */ +/* =============== */ + +/* 09-29-06 - patch from */ +/* Bobby Cheng, MathWorks */ + +/* Replace l.210 and l.393 */ +/* IF( MAX( ABSAKK, COLMAX ).EQ.ZERO ) THEN */ +/* by */ +/* IF( (MAX( ABSAKK, COLMAX ).EQ.ZERO) .OR. DISNAN(ABSAKK) ) THEN */ + +/* 01-01-96 - Based on modifications by */ +/* J. Lewis, Boeing Computer Services Company */ +/* A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA */ + +/* If UPLO = 'U', then A = U*D*U', where */ +/* U = P(n)*U(n)* ... *P(k)U(k)* ..., */ +/* i.e., U is a product of terms P(k)*U(k), where k decreases from n to */ +/* 1 in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1 */ +/* and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as */ +/* defined by IPIV(k), and U(k) is a unit upper triangular matrix, such */ +/* that if the diagonal block D(k) is of order s (s = 1 or 2), then */ + +/* ( I v 0 ) k-s */ +/* U(k) = ( 0 I 0 ) s */ +/* ( 0 0 I ) n-k */ +/* k-s s n-k */ + +/* If s = 1, D(k) overwrites A(k,k), and v overwrites A(1:k-1,k). */ +/* If s = 2, the upper triangle of D(k) overwrites A(k-1,k-1), A(k-1,k), */ +/* and A(k,k), and v overwrites A(1:k-2,k-1:k). */ + +/* If UPLO = 'L', then A = L*D*L', where */ +/* L = P(1)*L(1)* ... *P(k)*L(k)* ..., */ +/* i.e., L is a product of terms P(k)*L(k), where k increases from 1 to */ +/* n in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1 */ +/* and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as */ +/* defined by IPIV(k), and L(k) is a unit lower triangular matrix, such */ +/* that if the diagonal block D(k) is of order s (s = 1 or 2), then */ + +/* ( I 0 0 ) k-1 */ +/* L(k) = ( 0 I 0 ) s */ +/* ( 0 v I ) n-k-s+1 */ +/* k-1 s n-k-s+1 */ + +/* If s = 1, D(k) overwrites A(k,k), and v overwrites A(k+1:n,k). */ +/* If s = 2, the lower triangle of D(k) overwrites A(k,k), A(k+1,k), */ +/* and A(k+1,k+1), and v overwrites A(k+2:n,k:k+1). */ + +/* ===================================================================== */ + +/* .. Parameters .. */ +/* .. */ +/* .. Local Scalars .. */ +/* .. */ +/* .. External Functions .. */ +/* .. */ +/* .. External Subroutines .. */ +/* .. */ +/* .. Intrinsic Functions .. */ +/* .. */ +/* .. Statement Functions .. */ +/* .. */ +/* .. Statement Function definitions .. */ +/* .. */ +/* .. Executable Statements .. */ + +/* Test the input parameters. */ + + /* Parameter adjustments */ + a_dim1 = *lda; + a_offset = 1 + a_dim1; + a -= a_offset; + --ipiv; + + /* 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_("ZHETF2", &i__1); + return 0; + } + +/* Initialize ALPHA for use in choosing pivot block size. */ + + alpha = (sqrt(17.) + 1.) / 8.; + + if (upper) { + +/* Factorize A as U*D*U' using the upper triangle of A */ + +/* K is the main loop index, decreasing from N to 1 in steps of */ +/* 1 or 2 */ + + k = *n; +L10: + +/* If K < 1, exit from loop */ + + if (k < 1) { + goto L90; + } + kstep = 1; + +/* Determine rows and columns to be interchanged and whether */ +/* a 1-by-1 or 2-by-2 pivot block will be used */ + + i__1 = k + k * a_dim1; + absakk = (d__1 = a[i__1].r, 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 > 1) { + i__1 = k - 1; + imax = izamax_(&i__1, &a[k * a_dim1 + 1], &c__1); + i__1 = imax + k * a_dim1; + colmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[imax + + k * a_dim1]), abs(d__2)); + } else { + colmax = 0.; + } + + if (max(absakk,colmax) == 0. || disnan_(&absakk)) { + +/* Column K is zero or contains a NaN: set INFO and continue */ + + if (*info == 0) { + *info = k; + } + kp = k; + i__1 = k + k * a_dim1; + i__2 = k + k * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + } else { + if (absakk >= alpha * colmax) { + +/* no interchange, use 1-by-1 pivot block */ + + kp = k; + } else { + +/* JMAX is the column-index of the largest off-diagonal */ +/* element in row IMAX, and ROWMAX is its absolute value */ + + i__1 = k - imax; + jmax = imax + izamax_(&i__1, &a[imax + (imax + 1) * a_dim1], + lda); + i__1 = imax + jmax * a_dim1; + rowmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[ + imax + jmax * a_dim1]), abs(d__2)); + if (imax > 1) { + i__1 = imax - 1; + jmax = izamax_(&i__1, &a[imax * a_dim1 + 1], &c__1); +/* Computing MAX */ + i__1 = jmax + imax * a_dim1; + d__3 = rowmax, d__4 = (d__1 = a[i__1].r, abs(d__1)) + ( + d__2 = d_imag(&a[jmax + imax * a_dim1]), abs(d__2) + ); + rowmax = max(d__3,d__4); + } + + if (absakk >= alpha * colmax * (colmax / rowmax)) { + +/* no interchange, use 1-by-1 pivot block */ + + kp = k; + } else /* if(complicated condition) */ { + i__1 = imax + imax * a_dim1; + if ((d__1 = a[i__1].r, abs(d__1)) >= alpha * rowmax) { + +/* interchange rows and columns K and IMAX, use 1-by-1 */ +/* pivot block */ + + kp = imax; + } else { + +/* interchange rows and columns K-1 and IMAX, use 2-by-2 */ +/* pivot block */ + + kp = imax; + kstep = 2; + } + } + } + + kk = k - kstep + 1; + if (kp != kk) { + +/* Interchange rows and columns KK and KP in the leading */ +/* submatrix A(1:k,1:k) */ + + i__1 = kp - 1; + zswap_(&i__1, &a[kk * a_dim1 + 1], &c__1, &a[kp * a_dim1 + 1], + &c__1); + i__1 = kk - 1; + for (j = kp + 1; j <= i__1; ++j) { + d_cnjg(&z__1, &a[j + kk * a_dim1]); + t.r = z__1.r, t.i = z__1.i; + i__2 = j + kk * a_dim1; + d_cnjg(&z__1, &a[kp + j * a_dim1]); + a[i__2].r = z__1.r, a[i__2].i = z__1.i; + i__2 = kp + j * a_dim1; + a[i__2].r = t.r, a[i__2].i = t.i; +/* L20: */ + } + i__1 = kp + kk * a_dim1; + d_cnjg(&z__1, &a[kp + kk * a_dim1]); + a[i__1].r = z__1.r, a[i__1].i = z__1.i; + i__1 = kk + kk * a_dim1; + r1 = a[i__1].r; + i__1 = kk + kk * a_dim1; + i__2 = kp + kp * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + i__1 = kp + kp * a_dim1; + a[i__1].r = r1, a[i__1].i = 0.; + if (kstep == 2) { + i__1 = k + k * a_dim1; + i__2 = k + k * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + i__1 = k - 1 + k * a_dim1; + t.r = a[i__1].r, t.i = a[i__1].i; + i__1 = k - 1 + k * a_dim1; + i__2 = kp + k * a_dim1; + a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i; + i__1 = kp + k * a_dim1; + a[i__1].r = t.r, a[i__1].i = t.i; + } + } else { + i__1 = k + k * a_dim1; + i__2 = k + k * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + if (kstep == 2) { + i__1 = k - 1 + (k - 1) * a_dim1; + i__2 = k - 1 + (k - 1) * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + } + } + +/* Update the leading submatrix */ + + if (kstep == 1) { + +/* 1-by-1 pivot block D(k): column k now holds */ + +/* W(k) = U(k)*D(k) */ + +/* where U(k) is the k-th column of U */ + +/* Perform a rank-1 update of A(1:k-1,1:k-1) as */ + +/* A := A - U(k)*D(k)*U(k)' = A - W(k)*1/D(k)*W(k)' */ + + i__1 = k + k * a_dim1; + r1 = 1. / a[i__1].r; + i__1 = k - 1; + d__1 = -r1; + zher_(uplo, &i__1, &d__1, &a[k * a_dim1 + 1], &c__1, &a[ + a_offset], lda); + +/* Store U(k) in column k */ + + i__1 = k - 1; + zdscal_(&i__1, &r1, &a[k * a_dim1 + 1], &c__1); + } else { + +/* 2-by-2 pivot block D(k): columns k and k-1 now hold */ + +/* ( 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 */ + +/* Perform a rank-2 update of A(1:k-2,1:k-2) as */ + +/* A := A - ( U(k-1) U(k) )*D(k)*( U(k-1) U(k) )' */ +/* = A - ( W(k-1) W(k) )*inv(D(k))*( W(k-1) W(k) )' */ + + if (k > 2) { + + i__1 = k - 1 + k * a_dim1; + d__1 = a[i__1].r; + d__2 = d_imag(&a[k - 1 + k * a_dim1]); + d__ = dlapy2_(&d__1, &d__2); + i__1 = k - 1 + (k - 1) * a_dim1; + d22 = a[i__1].r / d__; + i__1 = k + k * a_dim1; + d11 = a[i__1].r / d__; + tt = 1. / (d11 * d22 - 1.); + i__1 = k - 1 + k * a_dim1; + z__1.r = a[i__1].r / d__, z__1.i = a[i__1].i / d__; + d12.r = z__1.r, d12.i = z__1.i; + d__ = tt / d__; + + for (j = k - 2; j >= 1; --j) { + i__1 = j + (k - 1) * a_dim1; + z__3.r = d11 * a[i__1].r, z__3.i = d11 * a[i__1].i; + d_cnjg(&z__5, &d12); + i__2 = j + k * a_dim1; + z__4.r = z__5.r * a[i__2].r - z__5.i * a[i__2].i, + z__4.i = z__5.r * a[i__2].i + z__5.i * a[i__2] + .r; + z__2.r = z__3.r - z__4.r, z__2.i = z__3.i - z__4.i; + z__1.r = d__ * z__2.r, z__1.i = d__ * z__2.i; + wkm1.r = z__1.r, wkm1.i = z__1.i; + i__1 = j + k * a_dim1; + z__3.r = d22 * a[i__1].r, z__3.i = d22 * a[i__1].i; + i__2 = j + (k - 1) * a_dim1; + z__4.r = d12.r * a[i__2].r - d12.i * a[i__2].i, + z__4.i = d12.r * a[i__2].i + d12.i * a[i__2] + .r; + z__2.r = z__3.r - z__4.r, z__2.i = z__3.i - z__4.i; + z__1.r = d__ * z__2.r, z__1.i = d__ * z__2.i; + wk.r = z__1.r, wk.i = z__1.i; + for (i__ = j; i__ >= 1; --i__) { + i__1 = i__ + j * a_dim1; + i__2 = i__ + j * a_dim1; + i__3 = i__ + k * a_dim1; + d_cnjg(&z__4, &wk); + z__3.r = a[i__3].r * z__4.r - a[i__3].i * z__4.i, + z__3.i = a[i__3].r * z__4.i + a[i__3].i * + z__4.r; + z__2.r = a[i__2].r - z__3.r, z__2.i = a[i__2].i - + z__3.i; + i__4 = i__ + (k - 1) * a_dim1; + d_cnjg(&z__6, &wkm1); + z__5.r = a[i__4].r * z__6.r - a[i__4].i * z__6.i, + z__5.i = a[i__4].r * z__6.i + a[i__4].i * + z__6.r; + z__1.r = z__2.r - z__5.r, z__1.i = z__2.i - + z__5.i; + a[i__1].r = z__1.r, a[i__1].i = z__1.i; +/* L30: */ + } + i__1 = j + k * a_dim1; + a[i__1].r = wk.r, a[i__1].i = wk.i; + i__1 = j + (k - 1) * a_dim1; + a[i__1].r = wkm1.r, a[i__1].i = wkm1.i; + i__1 = j + j * a_dim1; + i__2 = j + j * a_dim1; + d__1 = a[i__2].r; + z__1.r = d__1, z__1.i = 0.; + a[i__1].r = z__1.r, a[i__1].i = z__1.i; +/* L40: */ + } + + } + + } + } + +/* 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; + + } else { + +/* Factorize A as L*D*L' using the lower triangle of A */ + +/* K is the main loop index, increasing from 1 to N in steps of */ +/* 1 or 2 */ + + k = 1; +L50: + +/* If K > N, exit from loop */ + + if (k > *n) { + goto L90; + } + kstep = 1; + +/* Determine rows and columns to be interchanged and whether */ +/* a 1-by-1 or 2-by-2 pivot block will be used */ + + i__1 = k + k * a_dim1; + absakk = (d__1 = a[i__1].r, 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 + izamax_(&i__1, &a[k + 1 + k * a_dim1], &c__1); + i__1 = imax + k * a_dim1; + colmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[imax + + k * a_dim1]), abs(d__2)); + } else { + colmax = 0.; + } + + if (max(absakk,colmax) == 0. || disnan_(&absakk)) { + +/* Column K is zero or contains a NaN: set INFO and continue */ + + if (*info == 0) { + *info = k; + } + kp = k; + i__1 = k + k * a_dim1; + i__2 = k + k * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + } else { + if (absakk >= alpha * colmax) { + +/* no interchange, use 1-by-1 pivot block */ + + kp = k; + } else { + +/* 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 + izamax_(&i__1, &a[imax + k * a_dim1], lda); + i__1 = imax + jmax * a_dim1; + rowmax = (d__1 = a[i__1].r, abs(d__1)) + (d__2 = d_imag(&a[ + imax + jmax * a_dim1]), abs(d__2)); + if (imax < *n) { + i__1 = *n - imax; + jmax = imax + izamax_(&i__1, &a[imax + 1 + imax * a_dim1], + &c__1); +/* Computing MAX */ + i__1 = jmax + imax * a_dim1; + d__3 = rowmax, d__4 = (d__1 = a[i__1].r, abs(d__1)) + ( + d__2 = d_imag(&a[jmax + imax * a_dim1]), abs(d__2) + ); + rowmax = max(d__3,d__4); + } + + if (absakk >= alpha * colmax * (colmax / rowmax)) { + +/* no interchange, use 1-by-1 pivot block */ + + kp = k; + } else /* if(complicated condition) */ { + i__1 = imax + imax * a_dim1; + if ((d__1 = a[i__1].r, abs(d__1)) >= alpha * rowmax) { + +/* interchange rows and columns K and IMAX, use 1-by-1 */ +/* pivot block */ + + kp = imax; + } else { + +/* interchange rows and columns K+1 and IMAX, use 2-by-2 */ +/* pivot block */ + + kp = imax; + kstep = 2; + } + } + } + + kk = k + kstep - 1; + if (kp != kk) { + +/* Interchange rows and columns KK and KP in the trailing */ +/* submatrix A(k:n,k:n) */ + + if (kp < *n) { + i__1 = *n - kp; + zswap_(&i__1, &a[kp + 1 + kk * a_dim1], &c__1, &a[kp + 1 + + kp * a_dim1], &c__1); + } + i__1 = kp - 1; + for (j = kk + 1; j <= i__1; ++j) { + d_cnjg(&z__1, &a[j + kk * a_dim1]); + t.r = z__1.r, t.i = z__1.i; + i__2 = j + kk * a_dim1; + d_cnjg(&z__1, &a[kp + j * a_dim1]); + a[i__2].r = z__1.r, a[i__2].i = z__1.i; + i__2 = kp + j * a_dim1; + a[i__2].r = t.r, a[i__2].i = t.i; +/* L60: */ + } + i__1 = kp + kk * a_dim1; + d_cnjg(&z__1, &a[kp + kk * a_dim1]); + a[i__1].r = z__1.r, a[i__1].i = z__1.i; + i__1 = kk + kk * a_dim1; + r1 = a[i__1].r; + i__1 = kk + kk * a_dim1; + i__2 = kp + kp * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + i__1 = kp + kp * a_dim1; + a[i__1].r = r1, a[i__1].i = 0.; + if (kstep == 2) { + i__1 = k + k * a_dim1; + i__2 = k + k * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + i__1 = k + 1 + k * a_dim1; + t.r = a[i__1].r, t.i = a[i__1].i; + i__1 = k + 1 + k * a_dim1; + i__2 = kp + k * a_dim1; + a[i__1].r = a[i__2].r, a[i__1].i = a[i__2].i; + i__1 = kp + k * a_dim1; + a[i__1].r = t.r, a[i__1].i = t.i; + } + } else { + i__1 = k + k * a_dim1; + i__2 = k + k * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + if (kstep == 2) { + i__1 = k + 1 + (k + 1) * a_dim1; + i__2 = k + 1 + (k + 1) * a_dim1; + d__1 = a[i__2].r; + a[i__1].r = d__1, a[i__1].i = 0.; + } + } + +/* Update the trailing submatrix */ + + if (kstep == 1) { + +/* 1-by-1 pivot block D(k): column k now holds */ + +/* W(k) = L(k)*D(k) */ + +/* where L(k) is the k-th column of L */ + + if (k < *n) { + +/* Perform a rank-1 update of A(k+1:n,k+1:n) as */ + +/* A := A - L(k)*D(k)*L(k)' = A - W(k)*(1/D(k))*W(k)' */ + + i__1 = k + k * a_dim1; + r1 = 1. / a[i__1].r; + i__1 = *n - k; + d__1 = -r1; + zher_(uplo, &i__1, &d__1, &a[k + 1 + k * a_dim1], &c__1, & + a[k + 1 + (k + 1) * a_dim1], lda); + +/* Store L(k) in column K */ + + i__1 = *n - k; + zdscal_(&i__1, &r1, &a[k + 1 + k * a_dim1], &c__1); + } + } else { + +/* 2-by-2 pivot block D(k) */ + + if (k < *n - 1) { + +/* Perform a rank-2 update of A(k+2:n,k+2:n) as */ + +/* A := A - ( L(k) L(k+1) )*D(k)*( L(k) L(k+1) )' */ +/* = A - ( W(k) W(k+1) )*inv(D(k))*( W(k) W(k+1) )' */ + +/* where L(k) and L(k+1) are the k-th and (k+1)-th */ +/* columns of L */ + + i__1 = k + 1 + k * a_dim1; + d__1 = a[i__1].r; + d__2 = d_imag(&a[k + 1 + k * a_dim1]); + d__ = dlapy2_(&d__1, &d__2); + i__1 = k + 1 + (k + 1) * a_dim1; + d11 = a[i__1].r / d__; + i__1 = k + k * a_dim1; + d22 = a[i__1].r / d__; + tt = 1. / (d11 * d22 - 1.); + i__1 = k + 1 + k * a_dim1; + z__1.r = a[i__1].r / d__, z__1.i = a[i__1].i / d__; + d21.r = z__1.r, d21.i = z__1.i; + d__ = tt / d__; + + i__1 = *n; + for (j = k + 2; j <= i__1; ++j) { + i__2 = j + k * a_dim1; + z__3.r = d11 * a[i__2].r, z__3.i = d11 * a[i__2].i; + i__3 = j + (k + 1) * a_dim1; + z__4.r = d21.r * a[i__3].r - d21.i * a[i__3].i, + z__4.i = d21.r * a[i__3].i + d21.i * a[i__3] + .r; + z__2.r = z__3.r - z__4.r, z__2.i = z__3.i - z__4.i; + z__1.r = d__ * z__2.r, z__1.i = d__ * z__2.i; + wk.r = z__1.r, wk.i = z__1.i; + i__2 = j + (k + 1) * a_dim1; + z__3.r = d22 * a[i__2].r, z__3.i = d22 * a[i__2].i; + d_cnjg(&z__5, &d21); + i__3 = j + k * a_dim1; + z__4.r = z__5.r * a[i__3].r - z__5.i * a[i__3].i, + z__4.i = z__5.r * a[i__3].i + z__5.i * a[i__3] + .r; + z__2.r = z__3.r - z__4.r, z__2.i = z__3.i - z__4.i; + z__1.r = d__ * z__2.r, z__1.i = d__ * z__2.i; + wkp1.r = z__1.r, wkp1.i = z__1.i; + i__2 = *n; + for (i__ = j; i__ <= i__2; ++i__) { + i__3 = i__ + j * a_dim1; + i__4 = i__ + j * a_dim1; + i__5 = i__ + k * a_dim1; + d_cnjg(&z__4, &wk); + z__3.r = a[i__5].r * z__4.r - a[i__5].i * z__4.i, + z__3.i = a[i__5].r * z__4.i + a[i__5].i * + z__4.r; + z__2.r = a[i__4].r - z__3.r, z__2.i = a[i__4].i - + z__3.i; + i__6 = i__ + (k + 1) * a_dim1; + d_cnjg(&z__6, &wkp1); + z__5.r = a[i__6].r * z__6.r - a[i__6].i * z__6.i, + z__5.i = a[i__6].r * z__6.i + a[i__6].i * + z__6.r; + z__1.r = z__2.r - z__5.r, z__1.i = z__2.i - + z__5.i; + a[i__3].r = z__1.r, a[i__3].i = z__1.i; +/* L70: */ + } + i__2 = j + k * a_dim1; + a[i__2].r = wk.r, a[i__2].i = wk.i; + i__2 = j + (k + 1) * a_dim1; + a[i__2].r = wkp1.r, a[i__2].i = wkp1.i; + i__2 = j + j * a_dim1; + i__3 = j + j * a_dim1; + d__1 = a[i__3].r; + z__1.r = d__1, z__1.i = 0.; + a[i__2].r = z__1.r, a[i__2].i = z__1.i; +/* L80: */ + } + } + } + } + +/* 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 L50; + + } + +L90: + return 0; + +/* End of ZHETF2 */ + +} /* zhetf2_ */ |