--- /dev/null
+#include "clapack.h"
+
+/* Table of constant values */
+
+static integer c__2 = 2;
+static integer c__1 = 1;
+static doublereal c_b24 = 1.;
+static doublereal c_b26 = 0.;
+
+/* Subroutine */ int dlaeda_(integer *n, integer *tlvls, integer *curlvl,
+ integer *curpbm, integer *prmptr, integer *perm, integer *givptr,
+ integer *givcol, doublereal *givnum, doublereal *q, integer *qptr,
+ doublereal *z__, doublereal *ztemp, integer *info)
+{
+ /* System generated locals */
+ integer i__1, i__2, i__3;
+
+ /* Builtin functions */
+ integer pow_ii(integer *, integer *);
+ double sqrt(doublereal);
+
+ /* Local variables */
+ integer i__, k, mid, ptr;
+ extern /* Subroutine */ int drot_(integer *, doublereal *, integer *,
+ doublereal *, integer *, doublereal *, doublereal *);
+ integer curr, bsiz1, bsiz2, psiz1, psiz2, zptr1;
+ extern /* Subroutine */ int dgemv_(char *, integer *, integer *,
+ doublereal *, doublereal *, integer *, doublereal *, integer *,
+ doublereal *, doublereal *, integer *), dcopy_(integer *,
+ doublereal *, integer *, doublereal *, integer *), xerbla_(char *,
+ integer *);
+
+
+/* -- LAPACK routine (version 3.1) -- */
+/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/* November 2006 */
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* DLAEDA computes the Z vector corresponding to the merge step in the */
+/* CURLVLth step of the merge process with TLVLS steps for the CURPBMth */
+/* problem. */
+
+/* Arguments */
+/* ========= */
+
+/* N (input) INTEGER */
+/* The dimension of the symmetric tridiagonal matrix. N >= 0. */
+
+/* TLVLS (input) INTEGER */
+/* The total number of merging levels in the overall divide and */
+/* conquer tree. */
+
+/* CURLVL (input) INTEGER */
+/* The current level in the overall merge routine, */
+/* 0 <= curlvl <= tlvls. */
+
+/* CURPBM (input) INTEGER */
+/* The current problem in the current level in the overall */
+/* merge routine (counting from upper left to lower right). */
+
+/* PRMPTR (input) INTEGER array, dimension (N lg N) */
+/* Contains a list of pointers which indicate where in PERM a */
+/* level's permutation is stored. PRMPTR(i+1) - PRMPTR(i) */
+/* indicates the size of the permutation and incidentally the */
+/* size of the full, non-deflated problem. */
+
+/* PERM (input) INTEGER array, dimension (N lg N) */
+/* Contains the permutations (from deflation and sorting) to be */
+/* applied to each eigenblock. */
+
+/* GIVPTR (input) INTEGER array, dimension (N lg N) */
+/* Contains a list of pointers which indicate where in GIVCOL a */
+/* level's Givens rotations are stored. GIVPTR(i+1) - GIVPTR(i) */
+/* indicates the number of Givens rotations. */
+
+/* GIVCOL (input) INTEGER array, dimension (2, N lg N) */
+/* Each pair of numbers indicates a pair of columns to take place */
+/* in a Givens rotation. */
+
+/* GIVNUM (input) DOUBLE PRECISION array, dimension (2, N lg N) */
+/* Each number indicates the S value to be used in the */
+/* corresponding Givens rotation. */
+
+/* Q (input) DOUBLE PRECISION array, dimension (N**2) */
+/* Contains the square eigenblocks from previous levels, the */
+/* starting positions for blocks are given by QPTR. */
+
+/* QPTR (input) INTEGER array, dimension (N+2) */
+/* Contains a list of pointers which indicate where in Q an */
+/* eigenblock is stored. SQRT( QPTR(i+1) - QPTR(i) ) indicates */
+/* the size of the block. */
+
+/* Z (output) DOUBLE PRECISION array, dimension (N) */
+/* On output this vector contains the updating vector (the last */
+/* row of the first sub-eigenvector matrix and the first row of */
+/* the second sub-eigenvector matrix). */
+
+/* ZTEMP (workspace) DOUBLE PRECISION array, dimension (N) */
+
+/* INFO (output) INTEGER */
+/* = 0: successful exit. */
+/* < 0: if INFO = -i, the i-th argument had an illegal value. */
+
+/* Further Details */
+/* =============== */
+
+/* Based on contributions by */
+/* Jeff Rutter, Computer Science Division, University of California */
+/* at Berkeley, USA */
+
+/* ===================================================================== */
+
+/* .. Parameters .. */
+/* .. */
+/* .. Local Scalars .. */
+/* .. */
+/* .. External Subroutines .. */
+/* .. */
+/* .. Intrinsic Functions .. */
+/* .. */
+/* .. Executable Statements .. */
+
+/* Test the input parameters. */
+
+ /* Parameter adjustments */
+ --ztemp;
+ --z__;
+ --qptr;
+ --q;
+ givnum -= 3;
+ givcol -= 3;
+ --givptr;
+ --perm;
+ --prmptr;
+
+ /* Function Body */
+ *info = 0;
+
+ if (*n < 0) {
+ *info = -1;
+ }
+ if (*info != 0) {
+ i__1 = -(*info);
+ xerbla_("DLAEDA", &i__1);
+ return 0;
+ }
+
+/* Quick return if possible */
+
+ if (*n == 0) {
+ return 0;
+ }
+
+/* Determine location of first number in second half. */
+
+ mid = *n / 2 + 1;
+
+/* Gather last/first rows of appropriate eigenblocks into center of Z */
+
+ ptr = 1;
+
+/* Determine location of lowest level subproblem in the full storage */
+/* scheme */
+
+ i__1 = *curlvl - 1;
+ curr = ptr + *curpbm * pow_ii(&c__2, curlvl) + pow_ii(&c__2, &i__1) - 1;
+
+/* Determine size of these matrices. We add HALF to the value of */
+/* the SQRT in case the machine underestimates one of these square */
+/* roots. */
+
+ bsiz1 = (integer) (sqrt((doublereal) (qptr[curr + 1] - qptr[curr])) + .5);
+ bsiz2 = (integer) (sqrt((doublereal) (qptr[curr + 2] - qptr[curr + 1])) +
+ .5);
+ i__1 = mid - bsiz1 - 1;
+ for (k = 1; k <= i__1; ++k) {
+ z__[k] = 0.;
+/* L10: */
+ }
+ dcopy_(&bsiz1, &q[qptr[curr] + bsiz1 - 1], &bsiz1, &z__[mid - bsiz1], &
+ c__1);
+ dcopy_(&bsiz2, &q[qptr[curr + 1]], &bsiz2, &z__[mid], &c__1);
+ i__1 = *n;
+ for (k = mid + bsiz2; k <= i__1; ++k) {
+ z__[k] = 0.;
+/* L20: */
+ }
+
+/* Loop thru remaining levels 1 -> CURLVL applying the Givens */
+/* rotations and permutation and then multiplying the center matrices */
+/* against the current Z. */
+
+ ptr = pow_ii(&c__2, tlvls) + 1;
+ i__1 = *curlvl - 1;
+ for (k = 1; k <= i__1; ++k) {
+ i__2 = *curlvl - k;
+ i__3 = *curlvl - k - 1;
+ curr = ptr + *curpbm * pow_ii(&c__2, &i__2) + pow_ii(&c__2, &i__3) -
+ 1;
+ psiz1 = prmptr[curr + 1] - prmptr[curr];
+ psiz2 = prmptr[curr + 2] - prmptr[curr + 1];
+ zptr1 = mid - psiz1;
+
+/* Apply Givens at CURR and CURR+1 */
+
+ i__2 = givptr[curr + 1] - 1;
+ for (i__ = givptr[curr]; i__ <= i__2; ++i__) {
+ drot_(&c__1, &z__[zptr1 + givcol[(i__ << 1) + 1] - 1], &c__1, &
+ z__[zptr1 + givcol[(i__ << 1) + 2] - 1], &c__1, &givnum[(
+ i__ << 1) + 1], &givnum[(i__ << 1) + 2]);
+/* L30: */
+ }
+ i__2 = givptr[curr + 2] - 1;
+ for (i__ = givptr[curr + 1]; i__ <= i__2; ++i__) {
+ drot_(&c__1, &z__[mid - 1 + givcol[(i__ << 1) + 1]], &c__1, &z__[
+ mid - 1 + givcol[(i__ << 1) + 2]], &c__1, &givnum[(i__ <<
+ 1) + 1], &givnum[(i__ << 1) + 2]);
+/* L40: */
+ }
+ psiz1 = prmptr[curr + 1] - prmptr[curr];
+ psiz2 = prmptr[curr + 2] - prmptr[curr + 1];
+ i__2 = psiz1 - 1;
+ for (i__ = 0; i__ <= i__2; ++i__) {
+ ztemp[i__ + 1] = z__[zptr1 + perm[prmptr[curr] + i__] - 1];
+/* L50: */
+ }
+ i__2 = psiz2 - 1;
+ for (i__ = 0; i__ <= i__2; ++i__) {
+ ztemp[psiz1 + i__ + 1] = z__[mid + perm[prmptr[curr + 1] + i__] -
+ 1];
+/* L60: */
+ }
+
+/* Multiply Blocks at CURR and CURR+1 */
+
+/* Determine size of these matrices. We add HALF to the value of */
+/* the SQRT in case the machine underestimates one of these */
+/* square roots. */
+
+ bsiz1 = (integer) (sqrt((doublereal) (qptr[curr + 1] - qptr[curr])) +
+ .5);
+ bsiz2 = (integer) (sqrt((doublereal) (qptr[curr + 2] - qptr[curr + 1])
+ ) + .5);
+ if (bsiz1 > 0) {
+ dgemv_("T", &bsiz1, &bsiz1, &c_b24, &q[qptr[curr]], &bsiz1, &
+ ztemp[1], &c__1, &c_b26, &z__[zptr1], &c__1);
+ }
+ i__2 = psiz1 - bsiz1;
+ dcopy_(&i__2, &ztemp[bsiz1 + 1], &c__1, &z__[zptr1 + bsiz1], &c__1);
+ if (bsiz2 > 0) {
+ dgemv_("T", &bsiz2, &bsiz2, &c_b24, &q[qptr[curr + 1]], &bsiz2, &
+ ztemp[psiz1 + 1], &c__1, &c_b26, &z__[mid], &c__1);
+ }
+ i__2 = psiz2 - bsiz2;
+ dcopy_(&i__2, &ztemp[psiz1 + bsiz2 + 1], &c__1, &z__[mid + bsiz2], &
+ c__1);
+
+ i__2 = *tlvls - k;
+ ptr += pow_ii(&c__2, &i__2);
+/* L70: */
+ }
+
+ return 0;
+
+/* End of DLAEDA */
+
+} /* dlaeda_ */
projects / opencv / blobdiff