/* powell_newuoa.f -- translated by f2c (version 19961017).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* CC      SUBROUTINE NEWUOA (N,NPT,X,RHOBEG,RHOEND,IPRINT,MAXFUN,W) */
/* Subroutine */ int newuoa_(integer *n, integer *npt, doublereal *x, 
	doublereal *rhobeg, doublereal *rhoend, integer *maxfun, doublereal *
	w, integer *icode)
{
    static integer ndim, nptm, ibmat, izmat, id, np, iw;
    extern /* Subroutine */ int newuob_(integer *, integer *, doublereal *, 
	    doublereal *, doublereal *, integer *, doublereal *, doublereal *,
	     doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, integer *,
	     doublereal *, doublereal *, doublereal *, integer *);
    static integer igq, ihq, ixb, ifv, ipq, ivl, ixn, ixo, ixp;


/*    This subroutine seeks the least value of a function of many variable
s,*/
/*    by a trust region method that forms quadratic models by interpolatio
n.*/
/*     There can be some freedom in the interpolation conditions, which is
 */
/*    taken up by minimizing the Frobenius norm of the change to the secon
d*/
/*    derivative of the quadratic model, beginning with a zero matrix. The
*/
/*     arguments of the subroutine are as follows. */

/*     N must be set to the number of variables and must be at least two. 
*/
/*    NPT is the number of interpolation conditions. Its value must be in 
the*/
/*       interval [N+2,(N+1)(N+2)/2]. */
/*    Initial values of the variables must be set in X(1),X(2),...,X(N). T
hey*/
/*       will be changed to the values that give the least calculated F. 
*/
/*    RHOBEG and RHOEND must be set to the initial and final values of a t
rust*/
/*      region radius, so both must be positive with RHOEND<=RHOBEG. Typic
ally*/
/*      RHOBEG should be about one tenth of the greatest expected change t
o a*/
/*      variable, and RHOEND should indicate the accuracy that is required
 in*/
/*       the final values of the variables. */
/*CCC     The value of IPRINT should be set to 0, 1, 2 or 3, which control
s the*/
/*CCC       amount of printing. Specifically, there is no output if IPRINT
=0 and*/
/*CCC       there is output only at the return if IPRINT=1. Otherwise, eac
h new*/
/*CCC       value of RHO is printed, with the best vector of variables so 
far and*/
/*CCC       the corresponding value of the objective function. Further, ea
ch new*/
/* CCC       value of F with its variables are output if IPRINT=3. */
/*    MAXFUN must be set to an upper bound on the number of calls of CALFU
N.*/
/*    The array W will be used for working space. Its length must be at le
ast*/
/*     (NPT+13)*(NPT+N)+3*N*(N+3)/2. */

/*    SUBROUTINE CALFUN (N,X,F) must be provided by the user. It must set 
F to*/
/*    the value of the objective function for the variables X(1),X(2),...,
X(N).*/

/*    Partition the working space array, so that different parts of it can
 be*/
/*    treated separately by the subroutine that performs the main calculat
ion.*/

    /* Parameter adjustments */
    --w;
    --x;

    /* Function Body */
    np = *n + 1;
    nptm = *npt - np;
/* CC      IF (NPT .LT. N+2 .OR. NPT .GT. ((N+2)*NP)/2) THEN */
/* CC          PRINT 10 */
/* CC   10     FORMAT (/4X,'Return from NEWUOA because NPT is not in', */
/* CC     1      ' the required interval') */
/* CC          GO TO 20 */
/* CC      END IF */
    ndim = *npt + *n;
    ixb = 1;
    ixo = ixb + *n;
    ixn = ixo + *n;
    ixp = ixn + *n;
    ifv = ixp + *n * *npt;
    igq = ifv + *npt;
    ihq = igq + *n;
    ipq = ihq + *n * np / 2;
    ibmat = ipq + *npt;
    izmat = ibmat + ndim * *n;
    id = izmat + *npt * nptm;
    ivl = id + *n;
    iw = ivl + ndim;

/*     The above settings provide a partition of W for subroutine NEWUOB. 
*/
/*    The partition requires the first NPT*(NPT+N)+5*N*(N+3)/2 elements of
*/
/*     W plus the space that is needed by the last array of NEWUOB. */

/* CC      CALL NEWUOB (N,NPT,X,RHOBEG,RHOEND,IPRINT,MAXFUN,W(IXB), */
    newuob_(n, npt, &x[1], rhobeg, rhoend, maxfun, &w[ixb], &w[ixo], &w[ixn], 
	    &w[ixp], &w[ifv], &w[igq], &w[ihq], &w[ipq], &w[ibmat], &w[izmat],
	     &ndim, &w[id], &w[ivl], &w[iw], icode);
/* L20: */
    return 0;
} /* newuoa_ */

/* CC      SUBROUTINE NEWUOB (N,NPT,X,RHOBEG,RHOEND,IPRINT,MAXFUN,XBASE, */
/* Subroutine */ int newuob_(integer *n, integer *npt, doublereal *x, 
	doublereal *rhobeg, doublereal *rhoend, integer *maxfun, doublereal *
	xbase, doublereal *xopt, doublereal *xnew, doublereal *xpt, 
	doublereal *fval, doublereal *gq, doublereal *hq, doublereal *pq, 
	doublereal *bmat, doublereal *zmat, integer *ndim, doublereal *d__, 
	doublereal *vlag, doublereal *w, integer *icode)
{
    /* System generated locals */
    integer xpt_dim1, xpt_offset, bmat_dim1, bmat_offset, zmat_dim1, 
	    zmat_offset, i__1, i__2, i__3;
    doublereal d__1, d__2, d__3;

    /* Builtin functions */
    double sqrt(doublereal);

    /* Local variables */
    static doublereal fbeg, diff, half, beta;
    static integer nfmm;
    static doublereal gisq;
    static integer knew;
    static doublereal temp, suma, sumb, fopt, bsum, gqsq;
    static integer kopt, nptm;
    static doublereal zero, xipt, xjpt, sumz, f;
    static integer i__, j, k;
    static doublereal diffa, diffb, diffc, hdiag, alpha, delta, recip, reciq, 
	    fsave;
    static integer ksave, nfsav, itemp;
    static doublereal dnorm, ratio, dstep, tenth, vquad;
    static integer ktemp;
    static doublereal tempq;
    static integer itest;
    static doublereal rhosq;
    static integer ih, nf;
    extern /* Subroutine */ int biglag_(integer *, integer *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, integer *, integer *, 
	    integer *, doublereal *, doublereal *, doublereal *, doublereal *,
	     doublereal *, doublereal *, doublereal *, doublereal *);
    static integer nh, ip, jp;
    static doublereal dx;
    extern /* Subroutine */ int bigden_(integer *, integer *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, integer *, integer *, 
	    integer *, integer *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *);
    static integer np;
    extern /* Subroutine */ int calfun_(integer *, doublereal *, doublereal *)
	    , update_(integer *, integer *, doublereal *, doublereal *, 
	    integer *, integer *, doublereal *, doublereal *, integer *, 
	    doublereal *);
    static doublereal detrat, crvmin;
    static integer nftest;
    static doublereal distsq;
    extern /* Subroutine */ int trsapp_(integer *, integer *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *);
    static doublereal xoptsq;
    static integer nfm;
    static doublereal one;
    static integer idz;
    static doublereal dsq, rho;
    static integer ipt, jpt;
    static doublereal sum;


/*    The arguments N, NPT, X, RHOBEG, RHOEND, IPRINT and MAXFUN are ident
ical*/
/*       to the corresponding arguments in SUBROUTINE NEWUOA. */
/*    XBASE will hold a shift of origin that should reduce the contributio
ns*/
/*      from rounding errors to values of the model and Lagrange functions
.*/
/*     XOPT will be set to the displacement from XBASE of the vector of */
/*       variables that provides the least calculated F so far. */
/*     XNEW will be set to the displacement from XBASE of the vector of */
/*       variables for the current calculation of F. */
/*    XPT will contain the interpolation point coordinates relative to XBA
SE.*/
/*     FVAL will hold the values of F at the interpolation points. */
/*     GQ will hold the gradient of the quadratic model at XBASE. */
/*    HQ will hold the explicit second derivatives of the quadratic model.
*/
/*    PQ will contain the parameters of the implicit second derivatives of
*/
/*       the quadratic model. */
/*     BMAT will hold the last N columns of H. */
/*    ZMAT will hold the factorization of the leading NPT by NPT submatrix
 of*/
/*      H, this factorization being ZMAT times Diag(DZ) times ZMAT^T, wher
e*/
/*       the elements of DZ are plus or minus one, as specified by IDZ. */
/*     NDIM is the first dimension of BMAT and has the value NPT+N. */
/*     D is reserved for trial steps from XOPT. */
/*    VLAG will contain the values of the Lagrange functions at a new poin
t X.*/
/*      They are part of a product that requires VLAG to be of length NDIM
.*/
/*    The array W will be used for working space. Its length must be at le
ast*/
/*       10*NDIM = 10*(NPT+N). */

/*     Set some constants. */

    /* Parameter adjustments */
    zmat_dim1 = *npt;
    zmat_offset = zmat_dim1 + 1;
    zmat -= zmat_offset;
    xpt_dim1 = *npt;
    xpt_offset = xpt_dim1 + 1;
    xpt -= xpt_offset;
    --x;
    --xbase;
    --xopt;
    --xnew;
    --fval;
    --gq;
    --hq;
    --pq;
    bmat_dim1 = *ndim;
    bmat_offset = bmat_dim1 + 1;
    bmat -= bmat_offset;
    --d__;
    --vlag;
    --w;

    /* Function Body */
    half = .5;
    one = 1.;
    tenth = .1;
    zero = 0.;
    np = *n + 1;
    nh = *n * np / 2;
    nptm = *npt - np;
    nftest = max(*maxfun,1);

/*     Set the initial elements of XPT, BMAT, HQ, PQ and ZMAT to zero. */

    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
	xbase[j] = x[j];
	i__2 = *npt;
	for (k = 1; k <= i__2; ++k) {
/* L10: */
	    xpt[k + j * xpt_dim1] = zero;
	}
	i__2 = *ndim;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L20: */
	    bmat[i__ + j * bmat_dim1] = zero;
	}
    }
    i__2 = nh;
    for (ih = 1; ih <= i__2; ++ih) {
/* L30: */
	hq[ih] = zero;
    }
    i__2 = *npt;
    for (k = 1; k <= i__2; ++k) {
	pq[k] = zero;
	i__1 = nptm;
	for (j = 1; j <= i__1; ++j) {
/* L40: */
	    zmat[k + j * zmat_dim1] = zero;
	}
    }

/*    Begin the initialization procedure. NF becomes one more than the num
ber*/
/*    of function values so far. The coordinates of the displacement of th
e*/
/*     next initial interpolation point from XBASE are set in XPT(NF,.). 
*/

    rhosq = *rhobeg * *rhobeg;
    recip = one / rhosq;
    reciq = sqrt(half) / rhosq;
    nf = 0;
    *icode = 0;
L50:
    nfm = nf;
    nfmm = nf - *n;
    ++nf;
    if (nfm <= *n << 1) {
	if (nfm >= 1 && nfm <= *n) {
	    xpt[nf + nfm * xpt_dim1] = *rhobeg;
	} else if (nfm > *n) {
	    xpt[nf + nfmm * xpt_dim1] = -(*rhobeg);
	}
    } else {
	itemp = (nfmm - 1) / *n;
	jpt = nfm - itemp * *n - *n;
	ipt = jpt + itemp;
	if (ipt > *n) {
	    itemp = jpt;
	    jpt = ipt - *n;
	    ipt = itemp;
	}
	xipt = *rhobeg;
	if (fval[ipt + np] < fval[ipt + 1]) {
	    xipt = -xipt;
	}
	xjpt = *rhobeg;
	if (fval[jpt + np] < fval[jpt + 1]) {
	    xjpt = -xjpt;
	}
	xpt[nf + ipt * xpt_dim1] = xipt;
	xpt[nf + jpt * xpt_dim1] = xjpt;
    }

/*     Calculate the next value of F, label 70 being reached immediately 
*/
/*    after this calculation. The least function value so far and its inde
x*/
/*     are required. */

    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
/* L60: */
	x[j] = xpt[nf + j * xpt_dim1] + xbase[j];
    }
    goto L310;
L70:
    fval[nf] = f;
    if (nf == 1) {
	fbeg = f;
	fopt = f;
	kopt = 1;
    } else if (f < fopt) {
	fopt = f;
	kopt = nf;
    }

/*     Set the nonzero initial elements of BMAT and the quadratic model in
 */
/*     the cases when NF is at most 2*N+1. */

    if (nfm <= *n << 1) {
	if (nfm >= 1 && nfm <= *n) {
	    gq[nfm] = (f - fbeg) / *rhobeg;
	    if (*npt < nf + *n) {
		bmat[nfm * bmat_dim1 + 1] = -one / *rhobeg;
		bmat[nf + nfm * bmat_dim1] = one / *rhobeg;
		bmat[*npt + nfm + nfm * bmat_dim1] = -half * rhosq;
	    }
	} else if (nfm > *n) {
	    bmat[nf - *n + nfmm * bmat_dim1] = half / *rhobeg;
	    bmat[nf + nfmm * bmat_dim1] = -half / *rhobeg;
	    zmat[nfmm * zmat_dim1 + 1] = -reciq - reciq;
	    zmat[nf - *n + nfmm * zmat_dim1] = reciq;
	    zmat[nf + nfmm * zmat_dim1] = reciq;
	    ih = nfmm * (nfmm + 1) / 2;
	    temp = (fbeg - f) / *rhobeg;
	    hq[ih] = (gq[nfmm] - temp) / *rhobeg;
	    gq[nfmm] = half * (gq[nfmm] + temp);
	}

/*    Set the off-diagonal second derivatives of the Lagrange function
s and*/
/*     the initial quadratic model. */

    } else {
	ih = ipt * (ipt - 1) / 2 + jpt;
	if (xipt < zero) {
	    ipt += *n;
	}
	if (xjpt < zero) {
	    jpt += *n;
	}
	zmat[nfmm * zmat_dim1 + 1] = recip;
	zmat[nf + nfmm * zmat_dim1] = recip;
	zmat[ipt + 1 + nfmm * zmat_dim1] = -recip;
	zmat[jpt + 1 + nfmm * zmat_dim1] = -recip;
	hq[ih] = (fbeg - fval[ipt + 1] - fval[jpt + 1] + f) / (xipt * xjpt);
    }
    if (nf < *npt) {
	goto L50;
    }

/*    Begin the iterative procedure, because the initial model is complete
.*/

    rho = *rhobeg;
    delta = rho;
    idz = 1;
    diffa = zero;
    diffb = zero;
    itest = 0;
    xoptsq = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	xopt[i__] = xpt[kopt + i__ * xpt_dim1];
/* L80: */
/* Computing 2nd power */
	d__1 = xopt[i__];
	xoptsq += d__1 * d__1;
    }
L90:
    nfsav = nf;

/*     Generate the next trust region step and test its length. Set KNEW 
*/
/*     to -1 if the purpose of the next F will be to improve the model. */

L100:
    knew = 0;
    trsapp_(n, npt, &xopt[1], &xpt[xpt_offset], &gq[1], &hq[1], &pq[1], &
	    delta, &d__[1], &w[1], &w[np], &w[np + *n], &w[np + (*n << 1)], &
	    crvmin);
    dsq = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* L110: */
/* Computing 2nd power */
	d__1 = d__[i__];
	dsq += d__1 * d__1;
    }
/* Computing MIN */
    d__1 = delta, d__2 = sqrt(dsq);
    dnorm = min(d__1,d__2);
    if (dnorm < half * rho) {
	knew = -1;
	delta = tenth * delta;
	ratio = -1.;
	if (delta <= rho * 1.5) {
	    delta = rho;
	}
	if (nf <= nfsav + 2) {
	    goto L460;
	}
	temp = crvmin * .125 * rho * rho;
/* Computing MAX */
	d__1 = max(diffa,diffb);
	if (temp <= max(d__1,diffc)) {
	    goto L460;
	}
	goto L490;
    }

/*    Shift XBASE if XOPT may be too far from XBASE. First make the change
s*/
/*     to BMAT that do not depend on ZMAT. */

L120:
    if (dsq <= xoptsq * .001) {
	tempq = xoptsq * .25;
	i__1 = *npt;
	for (k = 1; k <= i__1; ++k) {
	    sum = zero;
	    i__2 = *n;
	    for (i__ = 1; i__ <= i__2; ++i__) {
/* L130: */
		sum += xpt[k + i__ * xpt_dim1] * xopt[i__];
	    }
	    temp = pq[k] * sum;
	    sum -= half * xoptsq;
	    w[*npt + k] = sum;
	    i__2 = *n;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		gq[i__] += temp * xpt[k + i__ * xpt_dim1];
		xpt[k + i__ * xpt_dim1] -= half * xopt[i__];
		vlag[i__] = bmat[k + i__ * bmat_dim1];
		w[i__] = sum * xpt[k + i__ * xpt_dim1] + tempq * xopt[i__];
		ip = *npt + i__;
		i__3 = i__;
		for (j = 1; j <= i__3; ++j) {
/* L140: */
		    bmat[ip + j * bmat_dim1] = bmat[ip + j * bmat_dim1] + 
			    vlag[i__] * w[j] + w[i__] * vlag[j];
		}
	    }
	}

/*     Then the revisions of BMAT that depend on ZMAT are calculated. 
*/

	i__3 = nptm;
	for (k = 1; k <= i__3; ++k) {
	    sumz = zero;
	    i__2 = *npt;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		sumz += zmat[i__ + k * zmat_dim1];
/* L150: */
		w[i__] = w[*npt + i__] * zmat[i__ + k * zmat_dim1];
	    }
	    i__2 = *n;
	    for (j = 1; j <= i__2; ++j) {
		sum = tempq * sumz * xopt[j];
		i__1 = *npt;
		for (i__ = 1; i__ <= i__1; ++i__) {
/* L160: */
		    sum += w[i__] * xpt[i__ + j * xpt_dim1];
		}
		vlag[j] = sum;
		if (k < idz) {
		    sum = -sum;
		}
		i__1 = *npt;
		for (i__ = 1; i__ <= i__1; ++i__) {
/* L170: */
		    bmat[i__ + j * bmat_dim1] += sum * zmat[i__ + k * 
			    zmat_dim1];
		}
	    }
	    i__1 = *n;
	    for (i__ = 1; i__ <= i__1; ++i__) {
		ip = i__ + *npt;
		temp = vlag[i__];
		if (k < idz) {
		    temp = -temp;
		}
		i__2 = i__;
		for (j = 1; j <= i__2; ++j) {
/* L180: */
		    bmat[ip + j * bmat_dim1] += temp * vlag[j];
		}
	    }
	}

/*     The following instructions complete the shift of XBASE, includi
ng */
/*     the changes to the parameters of the quadratic model. */

	ih = 0;
	i__2 = *n;
	for (j = 1; j <= i__2; ++j) {
	    w[j] = zero;
	    i__1 = *npt;
	    for (k = 1; k <= i__1; ++k) {
		w[j] += pq[k] * xpt[k + j * xpt_dim1];
/* L190: */
		xpt[k + j * xpt_dim1] -= half * xopt[j];
	    }
	    i__1 = j;
	    for (i__ = 1; i__ <= i__1; ++i__) {
		++ih;
		if (i__ < j) {
		    gq[j] += hq[ih] * xopt[i__];
		}
		gq[i__] += hq[ih] * xopt[j];
		hq[ih] = hq[ih] + w[i__] * xopt[j] + xopt[i__] * w[j];
/* L200: */
		bmat[*npt + i__ + j * bmat_dim1] = bmat[*npt + j + i__ * 
			bmat_dim1];
	    }
	}
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    xbase[j] += xopt[j];
/* L210: */
	    xopt[j] = zero;
	}
	xoptsq = zero;
    }

/*     Pick the model step if KNEW is positive. A different choice of D */
/*     may be made later, if the choice of D by BIGLAG causes substantial 
*/
/*     cancellation in DENOM. */

    if (knew > 0) {
	biglag_(n, npt, &xopt[1], &xpt[xpt_offset], &bmat[bmat_offset], &zmat[
		zmat_offset], &idz, ndim, &knew, &dstep, &d__[1], &alpha, &
		vlag[1], &vlag[*npt + 1], &w[1], &w[np], &w[np + *n]);
    }

/*     Calculate VLAG and BETA for the current choice of D. The first NPT 
*/
/*     components of W_check will be held in W. */

    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
	suma = zero;
	sumb = zero;
	sum = zero;
	i__2 = *n;
	for (j = 1; j <= i__2; ++j) {
	    suma += xpt[k + j * xpt_dim1] * d__[j];
	    sumb += xpt[k + j * xpt_dim1] * xopt[j];
/* L220: */
	    sum += bmat[k + j * bmat_dim1] * d__[j];
	}
	w[k] = suma * (half * suma + sumb);
/* L230: */
	vlag[k] = sum;
    }
    beta = zero;
    i__1 = nptm;
    for (k = 1; k <= i__1; ++k) {
	sum = zero;
	i__2 = *npt;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L240: */
	    sum += zmat[i__ + k * zmat_dim1] * w[i__];
	}
	if (k < idz) {
	    beta += sum * sum;
	    sum = -sum;
	} else {
	    beta -= sum * sum;
	}
	i__2 = *npt;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L250: */
	    vlag[i__] += sum * zmat[i__ + k * zmat_dim1];
	}
    }
    bsum = zero;
    dx = zero;
    i__2 = *n;
    for (j = 1; j <= i__2; ++j) {
	sum = zero;
	i__1 = *npt;
	for (i__ = 1; i__ <= i__1; ++i__) {
/* L260: */
	    sum += w[i__] * bmat[i__ + j * bmat_dim1];
	}
	bsum += sum * d__[j];
	jp = *npt + j;
	i__1 = *n;
	for (k = 1; k <= i__1; ++k) {
/* L270: */
	    sum += bmat[jp + k * bmat_dim1] * d__[k];
	}
	vlag[jp] = sum;
	bsum += sum * d__[j];
/* L280: */
	dx += d__[j] * xopt[j];
    }
    beta = dx * dx + dsq * (xoptsq + dx + dx + half * dsq) + beta - bsum;
    vlag[kopt] += one;

/*    If KNEW is positive and if the cancellation in DENOM is unacceptable
,*/
/*    then BIGDEN calculates an alternative model step, XNEW being used fo
r*/
/*     working space. */

    if (knew > 0) {
/* Computing 2nd power */
	d__1 = vlag[knew];
	temp = one + alpha * beta / (d__1 * d__1);
	if (abs(temp) <= .8) {
	    bigden_(n, npt, &xopt[1], &xpt[xpt_offset], &bmat[bmat_offset], &
		    zmat[zmat_offset], &idz, ndim, &kopt, &knew, &d__[1], &w[
		    1], &vlag[1], &beta, &xnew[1], &w[*ndim + 1], &w[*ndim * 
		    6 + 1]);
	}
    }

/*     Calculate the next value of the objective function. */

L290:
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
	xnew[i__] = xopt[i__] + d__[i__];
/* L300: */
	x[i__] = xbase[i__] + xnew[i__];
    }
    ++nf;
L310:
    if (nf > nftest) {
	--nf;
/* CC          IF (IPRINT .GT. 0) PRINT 320 */
/* CC  320     FORMAT (/4X,'Return from NEWUOA because CALFUN has been
', */
/* CC     1      ' called MAXFUN times.') */
	goto L530;
    }
    calfun_(n, &x[1], &f);
/* CC      IF (IPRINT .EQ. 3) THEN */
/* CC          PRINT 330, NF,F,(X(I),I=1,N) */
/* CC  330      FORMAT (/4X,'Function number',I6,'    F =',1PD18.10, */
/* CC     1       '    The corresponding X is:'/(2X,5D15.6)) */
/* CC      END IF */
    if (nf <= *npt) {
	goto L70;
    }
    if (knew == -1) {
	goto L530;
    }

/*    Use the quadratic model to predict the change in F due to the step D
,*/
/*     and set DIFF to the error of this prediction. */

    vquad = zero;
    ih = 0;
    i__2 = *n;
    for (j = 1; j <= i__2; ++j) {
	vquad += d__[j] * gq[j];
	i__1 = j;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    ++ih;
	    temp = d__[i__] * xnew[j] + d__[j] * xopt[i__];
	    if (i__ == j) {
		temp = half * temp;
	    }
/* L340: */
	    vquad += temp * hq[ih];
	}
    }
    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
/* L350: */
	vquad += pq[k] * w[k];
    }
    diff = f - fopt - vquad;
    diffc = diffb;
    diffb = diffa;
    diffa = abs(diff);
    if (dnorm > rho) {
	nfsav = nf;
    }

/*    Update FOPT and XOPT if the new F is the least value of the objectiv
e*/
/*    function so far. The branch when KNEW is positive occurs if D is not
*/
/*     a trust region step. */

    fsave = fopt;
    if (f < fopt) {
	fopt = f;
	xoptsq = zero;
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    xopt[i__] = xnew[i__];
/* L360: */
/* Computing 2nd power */
	    d__1 = xopt[i__];
	    xoptsq += d__1 * d__1;
	}
    }
    ksave = knew;
    if (knew > 0) {
	goto L410;
    }

/*     Pick the next value of DELTA after a trust region step. */

    if (vquad >= zero) {
/* CC          IF (IPRINT .GT. 0) PRINT 370 */
/* CC  370     FORMAT (/4X,'Return from NEWUOA because a trust', */
/* CC     1      ' region step has failed to reduce Q.') */
	*icode = -1;
	goto L530;
    }
    ratio = (f - fsave) / vquad;
    if (ratio <= tenth) {
	delta = half * dnorm;
    } else if (ratio <= .7) {
/* Computing MAX */
	d__1 = half * delta;
	delta = max(d__1,dnorm);
    } else {
/* Computing MAX */
	d__1 = half * delta, d__2 = dnorm + dnorm;
	delta = max(d__1,d__2);
    }
    if (delta <= rho * 1.5) {
	delta = rho;
    }

/*    Set KNEW to the index of the next interpolation point to be deleted.
*/

/* Computing MAX */
    d__2 = tenth * delta;
/* Computing 2nd power */
    d__1 = max(d__2,rho);
    rhosq = d__1 * d__1;
    ktemp = 0;
    detrat = zero;
    if (f >= fsave) {
	ktemp = kopt;
	detrat = one;
    }
    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
	hdiag = zero;
	i__2 = nptm;
	for (j = 1; j <= i__2; ++j) {
	    temp = one;
	    if (j < idz) {
		temp = -one;
	    }
/* L380: */
/* Computing 2nd power */
	    d__1 = zmat[k + j * zmat_dim1];
	    hdiag += temp * (d__1 * d__1);
	}
/* Computing 2nd power */
	d__2 = vlag[k];
	temp = (d__1 = beta * hdiag + d__2 * d__2, abs(d__1));
	distsq = zero;
	i__2 = *n;
	for (j = 1; j <= i__2; ++j) {
/* L390: */
/* Computing 2nd power */
	    d__1 = xpt[k + j * xpt_dim1] - xopt[j];
	    distsq += d__1 * d__1;
	}
	if (distsq > rhosq) {
/* Computing 3rd power */
	    d__1 = distsq / rhosq, d__2 = d__1;
	    temp *= d__2 * (d__1 * d__1);
	}
	if (temp > detrat && k != ktemp) {
	    detrat = temp;
	    knew = k;
	}
/* L400: */
    }
    if (knew == 0) {
	goto L460;
    }

/*     Update BMAT, ZMAT and IDZ, so that the KNEW-th interpolation point 
*/
/*     can be moved. Begin the updating of the quadratic model, starting 
*/
/*     with the explicit second derivative term. */

L410:
    update_(n, npt, &bmat[bmat_offset], &zmat[zmat_offset], &idz, ndim, &vlag[
	    1], &beta, &knew, &w[1]);
    fval[knew] = f;
    ih = 0;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	temp = pq[knew] * xpt[knew + i__ * xpt_dim1];
	i__2 = i__;
	for (j = 1; j <= i__2; ++j) {
	    ++ih;
/* L420: */
	    hq[ih] += temp * xpt[knew + j * xpt_dim1];
	}
    }
    pq[knew] = zero;

/*    Update the other second derivative parameters, and then the gradient
*/
/*     vector of the model. Also include the new interpolation point. */

    i__2 = nptm;
    for (j = 1; j <= i__2; ++j) {
	temp = diff * zmat[knew + j * zmat_dim1];
	if (j < idz) {
	    temp = -temp;
	}
	i__1 = *npt;
	for (k = 1; k <= i__1; ++k) {
/* L440: */
	    pq[k] += temp * zmat[k + j * zmat_dim1];
	}
    }
    gqsq = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	gq[i__] += diff * bmat[knew + i__ * bmat_dim1];
/* Computing 2nd power */
	d__1 = gq[i__];
	gqsq += d__1 * d__1;
/* L450: */
	xpt[knew + i__ * xpt_dim1] = xnew[i__];
    }

/*    If a trust region step makes a small change to the objective functio
n,*/
/*    then calculate the gradient of the least Frobenius norm interpolant 
at*/
/*    XBASE, and store it in W, using VLAG for a vector of right hand side
s.*/

    if (ksave == 0 && delta == rho) {
	if (abs(ratio) > .01) {
	    itest = 0;
	} else {
	    i__1 = *npt;
	    for (k = 1; k <= i__1; ++k) {
/* L700: */
		vlag[k] = fval[k] - fval[kopt];
	    }
	    gisq = zero;
	    i__1 = *n;
	    for (i__ = 1; i__ <= i__1; ++i__) {
		sum = zero;
		i__2 = *npt;
		for (k = 1; k <= i__2; ++k) {
/* L710: */
		    sum += bmat[k + i__ * bmat_dim1] * vlag[k];
		}
		gisq += sum * sum;
/* L720: */
		w[i__] = sum;
	    }

/*    Test whether to replace the new quadratic model by the least
 Frobenius*/
/*     norm interpolant, making the replacement if the test is sat
isfied. */

	    ++itest;
	    if (gqsq < gisq * 100.) {
		itest = 0;
	    }
	    if (itest >= 3) {
		i__1 = *n;
		for (i__ = 1; i__ <= i__1; ++i__) {
/* L730: */
		    gq[i__] = w[i__];
		}
		i__1 = nh;
		for (ih = 1; ih <= i__1; ++ih) {
/* L740: */
		    hq[ih] = zero;
		}
		i__1 = nptm;
		for (j = 1; j <= i__1; ++j) {
		    w[j] = zero;
		    i__2 = *npt;
		    for (k = 1; k <= i__2; ++k) {
/* L750: */
			w[j] += vlag[k] * zmat[k + j * zmat_dim1];
		    }
/* L760: */
		    if (j < idz) {
			w[j] = -w[j];
		    }
		}
		i__1 = *npt;
		for (k = 1; k <= i__1; ++k) {
		    pq[k] = zero;
		    i__2 = nptm;
		    for (j = 1; j <= i__2; ++j) {
/* L770: */
			pq[k] += zmat[k + j * zmat_dim1] * w[j];
		    }
		}
		itest = 0;
	    }
	}
    }
    if (f < fsave) {
	kopt = knew;
    }

/*    If a trust region step has provided a sufficient decrease in F, then
*/
/*    branch for another trust region calculation. The case KSAVE>0 occurs
*/
/*     when the new function value was calculated by a model step. */

    if (f <= fsave + tenth * vquad) {
	goto L100;
    }
    if (ksave > 0) {
	goto L100;
    }

/*    Alternatively, find out if the interpolation points are close enough
*/
/*     to the best point so far. */

    knew = 0;
L460:
    distsq = delta * 4. * delta;
    i__2 = *npt;
    for (k = 1; k <= i__2; ++k) {
	sum = zero;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
/* L470: */
/* Computing 2nd power */
	    d__1 = xpt[k + j * xpt_dim1] - xopt[j];
	    sum += d__1 * d__1;
	}
	if (sum > distsq) {
	    knew = k;
	    distsq = sum;
	}
/* L480: */
    }

/*     If KNEW is positive, then set DSTEP, and branch back for the next 
*/
/*     iteration, which will generate a "model step". */

    if (knew > 0) {
/* Computing MAX */
/* Computing MIN */
	d__2 = tenth * sqrt(distsq), d__3 = half * delta;
	d__1 = min(d__2,d__3);
	dstep = max(d__1,rho);
	dsq = dstep * dstep;
	goto L120;
    }
    if (ratio > zero) {
	goto L100;
    }
    if (max(delta,dnorm) > rho) {
	goto L100;
    }

/*    The calculations with the current value of RHO are complete. Pick th
e*/
/*     next values of RHO and DELTA. */

L490:
    if (rho > *rhoend) {
	delta = half * rho;
	ratio = rho / *rhoend;
	if (ratio <= 16.) {
	    rho = *rhoend;
	} else if (ratio <= 250.) {
	    rho = sqrt(ratio) * *rhoend;
	} else {
	    rho = tenth * rho;
	}
	delta = max(delta,rho);
/* CC          IF (IPRINT .GE. 2) THEN */
/* CC              IF (IPRINT .GE. 3) PRINT 500 */
/* CC  500         FORMAT (5X) */
/* CC              PRINT 510, RHO,NF */
/* CC  510         FORMAT (/4X,'New RHO =',1PD11.4,5X,'Number of', */
/* CC     1          ' function values =',I6) */
/* CC              PRINT 520, FOPT,(XBASE(I)+XOPT(I),I=1,N) */
/* CC  520         FORMAT (4X,'Least value of F =',1PD23.15,9X, */
/* CC     1          'The corresponding X is:'/(2X,5D15.6)) */
/* CC          END IF */
	goto L90;
    }

/*     Return from the calculation, after another Newton-Raphson step, if 
*/
/*     it is too short to have been tried before. */

    if (knew == -1) {
	goto L290;
    }
L530:
    if (fopt <= f) {
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L540: */
	    x[i__] = xbase[i__] + xopt[i__];
	}
	f = fopt;
    }
/* CC      IF (IPRINT .GE. 1) THEN */
/* CC          PRINT 550, NF */
/* CC  550     FORMAT (/4X,'At the return from NEWUOA',5X, */
/* CC     1      'Number of function values =',I6) */
/* CC          PRINT 520, F,(X(I),I=1,N) */
/* CC      END IF */
    if (*icode == 0) {
	*icode = nf;
    }
    return 0;
} /* newuob_ */

/* Subroutine */ int trsapp_(integer *n, integer *npt, doublereal *xopt, 
	doublereal *xpt, doublereal *gq, doublereal *hq, doublereal *pq, 
	doublereal *delta, doublereal *step, doublereal *d__, doublereal *g, 
	doublereal *hd, doublereal *hs, doublereal *crvmin)
{
    /* System generated locals */
    integer xpt_dim1, xpt_offset, i__1, i__2;
    doublereal d__1, d__2;

    /* Builtin functions */
    double atan(doublereal), sqrt(doublereal), cos(doublereal), sin(
	    doublereal);

    /* Local variables */
    static doublereal qadd, half, qbeg, qred, qmin, temp, qsav, qnew, zero;
    static integer i__, j;
    static doublereal ggbeg;
    static integer k;
    static doublereal alpha, angle, reduc;
    static integer iterc;
    static doublereal ggsav, delsq, tempa, tempb;
    static integer isave;
    static doublereal bstep, ratio, twopi, dd, cf, dg, gg;
    static integer ih;
    static doublereal ds, sg;
    static integer iu;
    static doublereal ss;
    static integer itersw;
    static doublereal dhd, dhs, cth, sgk, shs, sth, angtest;
    static integer itermax;


/*    N is the number of variables of a quadratic objective function, Q sa
y.*/
/*    The arguments NPT, XOPT, XPT, GQ, HQ and PQ have their usual meaning
s,*/
/*       in order to define the current quadratic model Q. */
/*     DELTA is the trust region radius, and has to be positive. */
/*     STEP will be set to the calculated trial step. */
/*     The arrays D, G, HD and HS will be used for working space. */
/*     CRVMIN will be set to the least curvature of H along the conjugate 
*/
/*       directions that occur, except that it is set to zero if STEP goes
 */
/*       all the way to the trust region boundary. */

/*    The calculation of STEP begins with the truncated conjugate gradient
*/
/*    method. If the boundary of the trust region is reached, then further
*/
/*     changes to STEP may be made, each one being in the 2D space spanned
 */
/*     by the current STEP and the corresponding gradient of Q. Thus STEP 
*/
/*    should provide a substantial reduction to Q within the trust region.
*/

/*     Initialization, which includes setting HD to H times XOPT. */

    /* Parameter adjustments */
    xpt_dim1 = *npt;
    xpt_offset = xpt_dim1 + 1;
    xpt -= xpt_offset;
    --xopt;
    --gq;
    --hq;
    --pq;
    --step;
    --d__;
    --g;
    --hd;
    --hs;

    /* Function Body */
    half = .5;
    zero = 0.;
    twopi = atan(1.) * 8.;
    delsq = *delta * *delta;
    iterc = 0;
    itermax = *n;
    itersw = itermax;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* L10: */
	d__[i__] = xopt[i__];
    }
    goto L170;

/*     Prepare for the first line search. */

L20:
    qred = zero;
    dd = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	step[i__] = zero;
	hs[i__] = zero;
	g[i__] = gq[i__] + hd[i__];
	d__[i__] = -g[i__];
/* L30: */
/* Computing 2nd power */
	d__1 = d__[i__];
	dd += d__1 * d__1;
    }
    *crvmin = zero;
    if (dd == zero) {
	goto L160;
    }
    ds = zero;
    ss = zero;
    gg = dd;
    ggbeg = gg;

/*     Calculate the step to the trust region boundary and the product HD.
 */

L40:
    ++iterc;
    temp = delsq - ss;
    bstep = temp / (ds + sqrt(ds * ds + dd * temp));
    goto L170;
L50:
    dhd = zero;
    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
/* L60: */
	dhd += d__[j] * hd[j];
    }

/*     Update CRVMIN and set the step-length ALPHA. */

    alpha = bstep;
    if (dhd > zero) {
	temp = dhd / dd;
	if (iterc == 1) {
	    *crvmin = temp;
	}
	*crvmin = min(*crvmin,temp);
/* Computing MIN */
	d__1 = alpha, d__2 = gg / dhd;
	alpha = min(d__1,d__2);
    }
    qadd = alpha * (gg - half * alpha * dhd);
    qred += qadd;

/*     Update STEP and HS. */

    ggsav = gg;
    gg = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	step[i__] += alpha * d__[i__];
	hs[i__] += alpha * hd[i__];
/* L70: */
/* Computing 2nd power */
	d__1 = g[i__] + hs[i__];
	gg += d__1 * d__1;
    }

/*     Begin another conjugate direction iteration if required. */

    if (alpha < bstep) {
	if (qadd <= qred * .01) {
	    goto L160;
	}
	if (gg <= ggbeg * 1e-4) {
	    goto L160;
	}
	if (iterc == itermax) {
	    goto L160;
	}
	temp = gg / ggsav;
	dd = zero;
	ds = zero;
	ss = zero;
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    d__[i__] = temp * d__[i__] - g[i__] - hs[i__];
/* Computing 2nd power */
	    d__1 = d__[i__];
	    dd += d__1 * d__1;
	    ds += d__[i__] * step[i__];
/* L80: */
/* Computing 2nd power */
	    d__1 = step[i__];
	    ss += d__1 * d__1;
	}
	if (ds <= zero) {
	    goto L160;
	}
	if (ss < delsq) {
	    goto L40;
	}
    }
    *crvmin = zero;
    itersw = iterc;

/*     Test whether an alternative iteration is required. */

L90:
    if (gg <= ggbeg * 1e-4) {
	goto L160;
    }
    sg = zero;
    shs = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	sg += step[i__] * g[i__];
/* L100: */
	shs += step[i__] * hs[i__];
    }
    sgk = sg + shs;
    angtest = sgk / sqrt(gg * delsq);
    if (angtest <= -.99) {
	goto L160;
    }

/*     Begin the alternative iteration by calculating D and HD and some */
/*     scalar products. */

    ++iterc;
    temp = sqrt(delsq * gg - sgk * sgk);
    tempa = delsq / temp;
    tempb = sgk / temp;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* L110: */
	d__[i__] = tempa * (g[i__] + hs[i__]) - tempb * step[i__];
    }
    goto L170;
L120:
    dg = zero;
    dhd = zero;
    dhs = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	dg += d__[i__] * g[i__];
	dhd += hd[i__] * d__[i__];
/* L130: */
	dhs += hd[i__] * step[i__];
    }

/*     Seek the value of the angle that minimizes Q. */

    cf = half * (shs - dhd);
    qbeg = sg + cf;
    qsav = qbeg;
    qmin = qbeg;
    isave = 0;
    iu = 49;
    temp = twopi / (doublereal) (iu + 1);
    i__1 = iu;
    for (i__ = 1; i__ <= i__1; ++i__) {
	angle = (doublereal) i__ * temp;
	cth = cos(angle);
	sth = sin(angle);
	qnew = (sg + cf * cth) * cth + (dg + dhs * cth) * sth;
	if (qnew < qmin) {
	    qmin = qnew;
	    isave = i__;
	    tempa = qsav;
	} else if (i__ == isave + 1) {
	    tempb = qnew;
	}
/* L140: */
	qsav = qnew;
    }
    if ((doublereal) isave == zero) {
	tempa = qnew;
    }
    if (isave == iu) {
	tempb = qbeg;
    }
    angle = zero;
    if (tempa != tempb) {
	tempa -= qmin;
	tempb -= qmin;
	angle = half * (tempa - tempb) / (tempa + tempb);
    }
    angle = temp * ((doublereal) isave + angle);

/*     Calculate the new STEP and HS. Then test for convergence. */

    cth = cos(angle);
    sth = sin(angle);
    reduc = qbeg - (sg + cf * cth) * cth - (dg + dhs * cth) * sth;
    gg = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	step[i__] = cth * step[i__] + sth * d__[i__];
	hs[i__] = cth * hs[i__] + sth * hd[i__];
/* L150: */
/* Computing 2nd power */
	d__1 = g[i__] + hs[i__];
	gg += d__1 * d__1;
    }
    qred += reduc;
    ratio = reduc / qred;
    if (iterc < itermax && ratio > .01) {
	goto L90;
    }
L160:
    return 0;

/*    The following instructions act as a subroutine for setting the vecto
r*/
/*     HD to the vector D multiplied by the second derivative matrix of Q.
 */
/*    They are called from three different places, which are distinguished
*/
/*     by the value of ITERC. */

L170:
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* L180: */
	hd[i__] = zero;
    }
    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
	temp = zero;
	i__2 = *n;
	for (j = 1; j <= i__2; ++j) {
/* L190: */
	    temp += xpt[k + j * xpt_dim1] * d__[j];
	}
	temp *= pq[k];
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L200: */
	    hd[i__] += temp * xpt[k + i__ * xpt_dim1];
	}
    }
    ih = 0;
    i__2 = *n;
    for (j = 1; j <= i__2; ++j) {
	i__1 = j;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    ++ih;
	    if (i__ < j) {
		hd[j] += hq[ih] * d__[i__];
	    }
/* L210: */
	    hd[i__] += hq[ih] * d__[j];
	}
    }
    if (iterc == 0) {
	goto L20;
    }
    if (iterc <= itersw) {
	goto L50;
    }
    goto L120;
} /* trsapp_ */

/* Subroutine */ int update_(integer *n, integer *npt, doublereal *bmat, 
	doublereal *zmat, integer *idz, integer *ndim, doublereal *vlag, 
	doublereal *beta, integer *knew, doublereal *w)
{
    /* System generated locals */
    integer bmat_dim1, bmat_offset, zmat_dim1, zmat_offset, i__1, i__2;
    doublereal d__1, d__2;

    /* Builtin functions */
    double sqrt(doublereal);

    /* Local variables */
    static doublereal temp;
    static integer nptm;
    static doublereal zero;
    static integer i__, j, iflag;
    static doublereal scala, scalb, alpha, denom, tempa, tempb, tausq;
    static integer ja, jb, jl, jp;
    static doublereal one, tau;


/*    The arrays BMAT and ZMAT with IDZ are updated, in order to shift the
*/
/*    interpolation point that has index KNEW. On entry, VLAG contains the
*/
/*     components of the vector Theta*Wcheck+e_b of the updating formula 
*/
/*    (6.11), and BETA holds the value of the parameter that has this name
.*/
/*     The vector W is used for working space. */

/*     Set some constants. */

    /* Parameter adjustments */
    zmat_dim1 = *npt;
    zmat_offset = zmat_dim1 + 1;
    zmat -= zmat_offset;
    bmat_dim1 = *ndim;
    bmat_offset = bmat_dim1 + 1;
    bmat -= bmat_offset;
    --vlag;
    --w;

    /* Function Body */
    one = 1.;
    zero = 0.;
    nptm = *npt - *n - 1;

/*     Apply the rotations that put zeros in the KNEW-th row of ZMAT. */

    jl = 1;
    i__1 = nptm;
    for (j = 2; j <= i__1; ++j) {
	if (j == *idz) {
	    jl = *idz;
	} else if (zmat[*knew + j * zmat_dim1] != zero) {
/* Computing 2nd power */
	    d__1 = zmat[*knew + jl * zmat_dim1];
/* Computing 2nd power */
	    d__2 = zmat[*knew + j * zmat_dim1];
	    temp = sqrt(d__1 * d__1 + d__2 * d__2);
	    tempa = zmat[*knew + jl * zmat_dim1] / temp;
	    tempb = zmat[*knew + j * zmat_dim1] / temp;
	    i__2 = *npt;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		temp = tempa * zmat[i__ + jl * zmat_dim1] + tempb * zmat[i__ 
			+ j * zmat_dim1];
		zmat[i__ + j * zmat_dim1] = tempa * zmat[i__ + j * zmat_dim1] 
			- tempb * zmat[i__ + jl * zmat_dim1];
/* L10: */
		zmat[i__ + jl * zmat_dim1] = temp;
	    }
	    zmat[*knew + j * zmat_dim1] = zero;
	}
/* L20: */
    }

/*     Put the first NPT components of the KNEW-th column of HLAG into W, 
*/
/*     and calculate the parameters of the updating formula. */

    tempa = zmat[*knew + zmat_dim1];
    if (*idz >= 2) {
	tempa = -tempa;
    }
    if (jl > 1) {
	tempb = zmat[*knew + jl * zmat_dim1];
    }
    i__1 = *npt;
    for (i__ = 1; i__ <= i__1; ++i__) {
	w[i__] = tempa * zmat[i__ + zmat_dim1];
	if (jl > 1) {
	    w[i__] += tempb * zmat[i__ + jl * zmat_dim1];
	}
/* L30: */
    }
    alpha = w[*knew];
    tau = vlag[*knew];
    tausq = tau * tau;
    denom = alpha * *beta + tausq;
    vlag[*knew] -= one;

/*    Complete the updating of ZMAT when there is only one nonzero element
*/
/*    in the KNEW-th row of the new matrix ZMAT, but, if IFLAG is set to o
ne,*/
/*    then the first column of ZMAT will be exchanged with another one lat
er.*/

    iflag = 0;
    if (jl == 1) {
	temp = sqrt((abs(denom)));
	tempb = tempa / temp;
	tempa = tau / temp;
	i__1 = *npt;
	for (i__ = 1; i__ <= i__1; ++i__) {
/* L40: */
	    zmat[i__ + zmat_dim1] = tempa * zmat[i__ + zmat_dim1] - tempb * 
		    vlag[i__];
	}
	if (*idz == 1 && temp < zero) {
	    *idz = 2;
	}
	if (*idz >= 2 && temp >= zero) {
	    iflag = 1;
	}
    } else {

/*     Complete the updating of ZMAT in the alternative case. */

	ja = 1;
	if (*beta >= zero) {
	    ja = jl;
	}
	jb = jl + 1 - ja;
	temp = zmat[*knew + jb * zmat_dim1] / denom;
	tempa = temp * *beta;
	tempb = temp * tau;
	temp = zmat[*knew + ja * zmat_dim1];
	scala = one / sqrt(abs(*beta) * temp * temp + tausq);
	scalb = scala * sqrt((abs(denom)));
	i__1 = *npt;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    zmat[i__ + ja * zmat_dim1] = scala * (tau * zmat[i__ + ja * 
		    zmat_dim1] - temp * vlag[i__]);
/* L50: */
	    zmat[i__ + jb * zmat_dim1] = scalb * (zmat[i__ + jb * zmat_dim1] 
		    - tempa * w[i__] - tempb * vlag[i__]);
	}
	if (denom <= zero) {
	    if (*beta < zero) {
		++(*idz);
	    }
	    if (*beta >= zero) {
		iflag = 1;
	    }
	}
    }

/*     IDZ is reduced in the following case, and usually the first column 
*/
/*     of ZMAT is exchanged with a later one. */

    if (iflag == 1) {
	--(*idz);
	i__1 = *npt;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    temp = zmat[i__ + zmat_dim1];
	    zmat[i__ + zmat_dim1] = zmat[i__ + *idz * zmat_dim1];
/* L60: */
	    zmat[i__ + *idz * zmat_dim1] = temp;
	}
    }

/*     Finally, update the matrix BMAT. */

    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
	jp = *npt + j;
	w[jp] = bmat[*knew + j * bmat_dim1];
	tempa = (alpha * vlag[jp] - tau * w[jp]) / denom;
	tempb = (-(*beta) * w[jp] - tau * vlag[jp]) / denom;
	i__2 = jp;
	for (i__ = 1; i__ <= i__2; ++i__) {
	    bmat[i__ + j * bmat_dim1] = bmat[i__ + j * bmat_dim1] + tempa * 
		    vlag[i__] + tempb * w[i__];
	    if (i__ > *npt) {
		bmat[jp + (i__ - *npt) * bmat_dim1] = bmat[i__ + j * 
			bmat_dim1];
	    }
/* L70: */
	}
    }
    return 0;
} /* update_ */

/* Subroutine */ int bigden_(integer *n, integer *npt, doublereal *xopt, 
	doublereal *xpt, doublereal *bmat, doublereal *zmat, integer *idz, 
	integer *ndim, integer *kopt, integer *knew, doublereal *d__, 
	doublereal *w, doublereal *vlag, doublereal *beta, doublereal *s, 
	doublereal *wvec, doublereal *prod)
{
    /* System generated locals */
    integer xpt_dim1, xpt_offset, bmat_dim1, bmat_offset, zmat_dim1, 
	    zmat_offset, wvec_dim1, wvec_offset, prod_dim1, prod_offset, i__1,
	     i__2;
    doublereal d__1;

    /* Builtin functions */
    double atan(doublereal), sqrt(doublereal), cos(doublereal), sin(
	    doublereal);

    /* Local variables */
    static doublereal diff, half, temp;
    static integer ksav;
    static doublereal step;
    static integer nptm;
    static doublereal zero;
    static integer i__, j, k;
    static doublereal alpha, angle, denex[9];
    static integer iterc;
    static doublereal tempa, tempb, tempc;
    static integer isave;
    static doublereal ssden, dtest, quart, xoptd, twopi, xopts, dd;
    static integer jc;
    static doublereal ds;
    static integer ip, iu, nw;
    static doublereal ss, denold, denmax, densav, dstemp, sumold, sstemp, 
	    xoptsq, den[9], one, par[9], tau, sum, two;


/*     N is the number of variables. */
/*     NPT is the number of interpolation equations. */
/*     XOPT is the best interpolation point so far. */
/*     XPT contains the coordinates of the current interpolation points. 
*/
/*     BMAT provides the last N columns of H. */
/*    ZMAT and IDZ give a factorization of the first NPT by NPT submatrix 
of H.*/
/*     NDIM is the first dimension of BMAT and has the value NPT+N. */
/*     KOPT is the index of the optimal interpolation point. */
/*    KNEW is the index of the interpolation point that is going to be mov
ed.*/
/*    D will be set to the step from XOPT to the new point, and on entry i
t*/
/*      should be the D that was calculated by the last call of BIGLAG. Th
e*/
/*      length of the initial D provides a trust region bound on the final
 D.*/
/*     W will be set to Wcheck for the final choice of D. */
/*     VLAG will be set to Theta*Wcheck+e_b for the final choice of D. */
/*    BETA will be set to the value that will occur in the updating formul
a*/
/*      when the KNEW-th interpolation point is moved to its new position.
*/
/*    S, WVEC, PROD and the private arrays DEN, DENEX and PAR will be used
*/
/*       for working space. */

/*    D is calculated in a way that should provide a denominator with a la
rge*/
/*    modulus in the updating formula when the KNEW-th interpolation point
 is*/
/*     shifted to the new position XOPT+D. */

/*     Set some constants. */

    /* Parameter adjustments */
    zmat_dim1 = *npt;
    zmat_offset = zmat_dim1 + 1;
    zmat -= zmat_offset;
    xpt_dim1 = *npt;
    xpt_offset = xpt_dim1 + 1;
    xpt -= xpt_offset;
    --xopt;
    prod_dim1 = *ndim;
    prod_offset = prod_dim1 + 1;
    prod -= prod_offset;
    wvec_dim1 = *ndim;
    wvec_offset = wvec_dim1 + 1;
    wvec -= wvec_offset;
    bmat_dim1 = *ndim;
    bmat_offset = bmat_dim1 + 1;
    bmat -= bmat_offset;
    --d__;
    --w;
    --vlag;
    --s;

    /* Function Body */
    half = .5;
    one = 1.;
    quart = .25;
    two = 2.;
    zero = 0.;
    twopi = atan(one) * 8.;
    nptm = *npt - *n - 1;

/*     Store the first NPT elements of the KNEW-th column of H in W(N+1) 
*/
/*     to W(N+NPT). */

    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
/* L10: */
	w[*n + k] = zero;
    }
    i__1 = nptm;
    for (j = 1; j <= i__1; ++j) {
	temp = zmat[*knew + j * zmat_dim1];
	if (j < *idz) {
	    temp = -temp;
	}
	i__2 = *npt;
	for (k = 1; k <= i__2; ++k) {
/* L20: */
	    w[*n + k] += temp * zmat[k + j * zmat_dim1];
	}
    }
    alpha = w[*n + *knew];

/*    The initial search direction D is taken from the last call of BIGLAG
,*/
/*     and the initial S is set below, usually to the direction from X_OPT
 */
/*     to X_KNEW, but a different direction to an interpolation point may 
*/
/*     be chosen, in order to prevent S from being nearly parallel to D. 
*/

    dd = zero;
    ds = zero;
    ss = zero;
    xoptsq = zero;
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
/* Computing 2nd power */
	d__1 = d__[i__];
	dd += d__1 * d__1;
	s[i__] = xpt[*knew + i__ * xpt_dim1] - xopt[i__];
	ds += d__[i__] * s[i__];
/* Computing 2nd power */
	d__1 = s[i__];
	ss += d__1 * d__1;
/* L30: */
/* Computing 2nd power */
	d__1 = xopt[i__];
	xoptsq += d__1 * d__1;
    }
    if (ds * ds > dd * .99 * ss) {
	ksav = *knew;
	dtest = ds * ds / ss;
	i__2 = *npt;
	for (k = 1; k <= i__2; ++k) {
	    if (k != *kopt) {
		dstemp = zero;
		sstemp = zero;
		i__1 = *n;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    diff = xpt[k + i__ * xpt_dim1] - xopt[i__];
		    dstemp += d__[i__] * diff;
/* L40: */
		    sstemp += diff * diff;
		}
		if (dstemp * dstemp / sstemp < dtest) {
		    ksav = k;
		    dtest = dstemp * dstemp / sstemp;
		    ds = dstemp;
		    ss = sstemp;
		}
	    }
/* L50: */
	}
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L60: */
	    s[i__] = xpt[ksav + i__ * xpt_dim1] - xopt[i__];
	}
    }
    ssden = dd * ss - ds * ds;
    iterc = 0;
    densav = zero;

/*     Begin the iteration by overwriting S with a vector that has the */
/*     required length and direction. */

L70:
    ++iterc;
    temp = one / sqrt(ssden);
    xoptd = zero;
    xopts = zero;
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
	s[i__] = temp * (dd * s[i__] - ds * d__[i__]);
	xoptd += xopt[i__] * d__[i__];
/* L80: */
	xopts += xopt[i__] * s[i__];
    }

/*     Set the coefficients of the first two terms of BETA. */

    tempa = half * xoptd * xoptd;
    tempb = half * xopts * xopts;
    den[0] = dd * (xoptsq + half * dd) + tempa + tempb;
    den[1] = two * xoptd * dd;
    den[2] = two * xopts * dd;
    den[3] = tempa - tempb;
    den[4] = xoptd * xopts;
    for (i__ = 6; i__ <= 9; ++i__) {
/* L90: */
	den[i__ - 1] = zero;
    }

/*     Put the coefficients of Wcheck in WVEC. */

    i__2 = *npt;
    for (k = 1; k <= i__2; ++k) {
	tempa = zero;
	tempb = zero;
	tempc = zero;
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    tempa += xpt[k + i__ * xpt_dim1] * d__[i__];
	    tempb += xpt[k + i__ * xpt_dim1] * s[i__];
/* L100: */
	    tempc += xpt[k + i__ * xpt_dim1] * xopt[i__];
	}
	wvec[k + wvec_dim1] = quart * (tempa * tempa + tempb * tempb);
	wvec[k + (wvec_dim1 << 1)] = tempa * tempc;
	wvec[k + wvec_dim1 * 3] = tempb * tempc;
	wvec[k + (wvec_dim1 << 2)] = quart * (tempa * tempa - tempb * tempb);
/* L110: */
	wvec[k + wvec_dim1 * 5] = half * tempa * tempb;
    }
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
	ip = i__ + *npt;
	wvec[ip + wvec_dim1] = zero;
	wvec[ip + (wvec_dim1 << 1)] = d__[i__];
	wvec[ip + wvec_dim1 * 3] = s[i__];
	wvec[ip + (wvec_dim1 << 2)] = zero;
/* L120: */
	wvec[ip + wvec_dim1 * 5] = zero;
    }

/*     Put the coefficents of THETA*Wcheck in PROD. */

    for (jc = 1; jc <= 5; ++jc) {
	nw = *npt;
	if (jc == 2 || jc == 3) {
	    nw = *ndim;
	}
	i__2 = *npt;
	for (k = 1; k <= i__2; ++k) {
/* L130: */
	    prod[k + jc * prod_dim1] = zero;
	}
	i__2 = nptm;
	for (j = 1; j <= i__2; ++j) {
	    sum = zero;
	    i__1 = *npt;
	    for (k = 1; k <= i__1; ++k) {
/* L140: */
		sum += zmat[k + j * zmat_dim1] * wvec[k + jc * wvec_dim1];
	    }
	    if (j < *idz) {
		sum = -sum;
	    }
	    i__1 = *npt;
	    for (k = 1; k <= i__1; ++k) {
/* L150: */
		prod[k + jc * prod_dim1] += sum * zmat[k + j * zmat_dim1];
	    }
	}
	if (nw == *ndim) {
	    i__1 = *npt;
	    for (k = 1; k <= i__1; ++k) {
		sum = zero;
		i__2 = *n;
		for (j = 1; j <= i__2; ++j) {
/* L160: */
		    sum += bmat[k + j * bmat_dim1] * wvec[*npt + j + jc * 
			    wvec_dim1];
		}
/* L170: */
		prod[k + jc * prod_dim1] += sum;
	    }
	}
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    sum = zero;
	    i__2 = nw;
	    for (i__ = 1; i__ <= i__2; ++i__) {
/* L180: */
		sum += bmat[i__ + j * bmat_dim1] * wvec[i__ + jc * wvec_dim1];
	    }
/* L190: */
	    prod[*npt + j + jc * prod_dim1] = sum;
	}
    }

/*     Include in DEN the part of BETA that depends on THETA. */

    i__1 = *ndim;
    for (k = 1; k <= i__1; ++k) {
	sum = zero;
	for (i__ = 1; i__ <= 5; ++i__) {
	    par[i__ - 1] = half * prod[k + i__ * prod_dim1] * wvec[k + i__ * 
		    wvec_dim1];
/* L200: */
	    sum += par[i__ - 1];
	}
	den[0] = den[0] - par[0] - sum;
	tempa = prod[k + prod_dim1] * wvec[k + (wvec_dim1 << 1)] + prod[k + (
		prod_dim1 << 1)] * wvec[k + wvec_dim1];
	tempb = prod[k + (prod_dim1 << 1)] * wvec[k + (wvec_dim1 << 2)] + 
		prod[k + (prod_dim1 << 2)] * wvec[k + (wvec_dim1 << 1)];
	tempc = prod[k + prod_dim1 * 3] * wvec[k + wvec_dim1 * 5] + prod[k + 
		prod_dim1 * 5] * wvec[k + wvec_dim1 * 3];
	den[1] = den[1] - tempa - half * (tempb + tempc);
	den[5] -= half * (tempb - tempc);
	tempa = prod[k + prod_dim1] * wvec[k + wvec_dim1 * 3] + prod[k + 
		prod_dim1 * 3] * wvec[k + wvec_dim1];
	tempb = prod[k + (prod_dim1 << 1)] * wvec[k + wvec_dim1 * 5] + prod[k 
		+ prod_dim1 * 5] * wvec[k + (wvec_dim1 << 1)];
	tempc = prod[k + prod_dim1 * 3] * wvec[k + (wvec_dim1 << 2)] + prod[k 
		+ (prod_dim1 << 2)] * wvec[k + wvec_dim1 * 3];
	den[2] = den[2] - tempa - half * (tempb - tempc);
	den[6] -= half * (tempb + tempc);
	tempa = prod[k + prod_dim1] * wvec[k + (wvec_dim1 << 2)] + prod[k + (
		prod_dim1 << 2)] * wvec[k + wvec_dim1];
	den[3] = den[3] - tempa - par[1] + par[2];
	tempa = prod[k + prod_dim1] * wvec[k + wvec_dim1 * 5] + prod[k + 
		prod_dim1 * 5] * wvec[k + wvec_dim1];
	tempb = prod[k + (prod_dim1 << 1)] * wvec[k + wvec_dim1 * 3] + prod[k 
		+ prod_dim1 * 3] * wvec[k + (wvec_dim1 << 1)];
	den[4] = den[4] - tempa - half * tempb;
	den[7] = den[7] - par[3] + par[4];
	tempa = prod[k + (prod_dim1 << 2)] * wvec[k + wvec_dim1 * 5] + prod[k 
		+ prod_dim1 * 5] * wvec[k + (wvec_dim1 << 2)];
/* L210: */
	den[8] -= half * tempa;
    }

/*     Extend DEN so that it holds all the coefficients of DENOM. */

    sum = zero;
    for (i__ = 1; i__ <= 5; ++i__) {
/* Computing 2nd power */
	d__1 = prod[*knew + i__ * prod_dim1];
	par[i__ - 1] = half * (d__1 * d__1);
/* L220: */
	sum += par[i__ - 1];
    }
    denex[0] = alpha * den[0] + par[0] + sum;
    tempa = two * prod[*knew + prod_dim1] * prod[*knew + (prod_dim1 << 1)];
    tempb = prod[*knew + (prod_dim1 << 1)] * prod[*knew + (prod_dim1 << 2)];
    tempc = prod[*knew + prod_dim1 * 3] * prod[*knew + prod_dim1 * 5];
    denex[1] = alpha * den[1] + tempa + tempb + tempc;
    denex[5] = alpha * den[5] + tempb - tempc;
    tempa = two * prod[*knew + prod_dim1] * prod[*knew + prod_dim1 * 3];
    tempb = prod[*knew + (prod_dim1 << 1)] * prod[*knew + prod_dim1 * 5];
    tempc = prod[*knew + prod_dim1 * 3] * prod[*knew + (prod_dim1 << 2)];
    denex[2] = alpha * den[2] + tempa + tempb - tempc;
    denex[6] = alpha * den[6] + tempb + tempc;
    tempa = two * prod[*knew + prod_dim1] * prod[*knew + (prod_dim1 << 2)];
    denex[3] = alpha * den[3] + tempa + par[1] - par[2];
    tempa = two * prod[*knew + prod_dim1] * prod[*knew + prod_dim1 * 5];
    denex[4] = alpha * den[4] + tempa + prod[*knew + (prod_dim1 << 1)] * prod[
	    *knew + prod_dim1 * 3];
    denex[7] = alpha * den[7] + par[3] - par[4];
    denex[8] = alpha * den[8] + prod[*knew + (prod_dim1 << 2)] * prod[*knew + 
	    prod_dim1 * 5];

/*     Seek the value of the angle that maximizes the modulus of DENOM. */

    sum = denex[0] + denex[1] + denex[3] + denex[5] + denex[7];
    denold = sum;
    denmax = sum;
    isave = 0;
    iu = 49;
    temp = twopi / (doublereal) (iu + 1);
    par[0] = one;
    i__1 = iu;
    for (i__ = 1; i__ <= i__1; ++i__) {
	angle = (doublereal) i__ * temp;
	par[1] = cos(angle);
	par[2] = sin(angle);
	for (j = 4; j <= 8; j += 2) {
	    par[j - 1] = par[1] * par[j - 3] - par[2] * par[j - 2];
/* L230: */
	    par[j] = par[1] * par[j - 2] + par[2] * par[j - 3];
	}
	sumold = sum;
	sum = zero;
	for (j = 1; j <= 9; ++j) {
/* L240: */
	    sum += denex[j - 1] * par[j - 1];
	}
	if (abs(sum) > abs(denmax)) {
	    denmax = sum;
	    isave = i__;
	    tempa = sumold;
	} else if (i__ == isave + 1) {
	    tempb = sum;
	}
/* L250: */
    }
    if (isave == 0) {
	tempa = sum;
    }
    if (isave == iu) {
	tempb = denold;
    }
    step = zero;
    if (tempa != tempb) {
	tempa -= denmax;
	tempb -= denmax;
	step = half * (tempa - tempb) / (tempa + tempb);
    }
    angle = temp * ((doublereal) isave + step);

/*    Calculate the new parameters of the denominator, the new VLAG vector
*/
/*     and the new D. Then test for convergence. */

    par[1] = cos(angle);
    par[2] = sin(angle);
    for (j = 4; j <= 8; j += 2) {
	par[j - 1] = par[1] * par[j - 3] - par[2] * par[j - 2];
/* L260: */
	par[j] = par[1] * par[j - 2] + par[2] * par[j - 3];
    }
    *beta = zero;
    denmax = zero;
    for (j = 1; j <= 9; ++j) {
	*beta += den[j - 1] * par[j - 1];
/* L270: */
	denmax += denex[j - 1] * par[j - 1];
    }
    i__1 = *ndim;
    for (k = 1; k <= i__1; ++k) {
	vlag[k] = zero;
	for (j = 1; j <= 5; ++j) {
/* L280: */
	    vlag[k] += prod[k + j * prod_dim1] * par[j - 1];
	}
    }
    tau = vlag[*knew];
    dd = zero;
    tempa = zero;
    tempb = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	d__[i__] = par[1] * d__[i__] + par[2] * s[i__];
	w[i__] = xopt[i__] + d__[i__];
/* Computing 2nd power */
	d__1 = d__[i__];
	dd += d__1 * d__1;
	tempa += d__[i__] * w[i__];
/* L290: */
	tempb += w[i__] * w[i__];
    }
    if (iterc >= *n) {
	goto L340;
    }
    if (iterc > 1) {
	densav = max(densav,denold);
    }
    if (abs(denmax) <= abs(densav) * 1.1) {
	goto L340;
    }
    densav = denmax;

/*     Set S to half the gradient of the denominator with respect to D. */
/*     Then branch for the next iteration. */

    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	temp = tempa * xopt[i__] + tempb * d__[i__] - vlag[*npt + i__];
/* L300: */
	s[i__] = tau * bmat[*knew + i__ * bmat_dim1] + alpha * temp;
    }
    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
	sum = zero;
	i__2 = *n;
	for (j = 1; j <= i__2; ++j) {
/* L310: */
	    sum += xpt[k + j * xpt_dim1] * w[j];
	}
	temp = (tau * w[*n + k] - alpha * vlag[k]) * sum;
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L320: */
	    s[i__] += temp * xpt[k + i__ * xpt_dim1];
	}
    }
    ss = zero;
    ds = zero;
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
/* Computing 2nd power */
	d__1 = s[i__];
	ss += d__1 * d__1;
/* L330: */
	ds += d__[i__] * s[i__];
    }
    ssden = dd * ss - ds * ds;
    if (ssden >= dd * 1e-8 * ss) {
	goto L70;
    }

/*     Set the vector W before the RETURN from the subroutine. */

L340:
    i__2 = *ndim;
    for (k = 1; k <= i__2; ++k) {
	w[k] = zero;
	for (j = 1; j <= 5; ++j) {
/* L350: */
	    w[k] += wvec[k + j * wvec_dim1] * par[j - 1];
	}
    }
    vlag[*kopt] += one;
    return 0;
} /* bigden_ */

/* Subroutine */ int biglag_(integer *n, integer *npt, doublereal *xopt, 
	doublereal *xpt, doublereal *bmat, doublereal *zmat, integer *idz, 
	integer *ndim, integer *knew, doublereal *delta, doublereal *d__, 
	doublereal *alpha, doublereal *hcol, doublereal *gc, doublereal *gd, 
	doublereal *s, doublereal *w)
{
    /* System generated locals */
    integer xpt_dim1, xpt_offset, bmat_dim1, bmat_offset, zmat_dim1, 
	    zmat_offset, i__1, i__2;
    doublereal d__1;

    /* Builtin functions */
    double atan(doublereal), sqrt(doublereal), cos(doublereal), sin(
	    doublereal);

    /* Local variables */
    static doublereal half, temp, step;
    static integer nptm;
    static doublereal zero;
    static integer i__, j, k;
    static doublereal angle, scale, denom;
    static integer iterc, isave;
    static doublereal delsq, tempa, tempb, twopi, dd, gg;
    static integer iu;
    static doublereal sp, ss, taubeg, tauold, cf1, cf2, cf3, cf4, cf5, taumax,
	     dhd, cth, one, tau, sth, sum;


/*     N is the number of variables. */
/*     NPT is the number of interpolation equations. */
/*     XOPT is the best interpolation point so far. */
/*     XPT contains the coordinates of the current interpolation points. 
*/
/*     BMAT provides the last N columns of H. */
/*    ZMAT and IDZ give a factorization of the first NPT by NPT submatrix 
of H.*/
/*     NDIM is the first dimension of BMAT and has the value NPT+N. */
/*    KNEW is the index of the interpolation point that is going to be mov
ed.*/
/*     DELTA is the current trust region bound. */
/*     D will be set to the step from XOPT to the new point. */
/*     ALPHA will be set to the KNEW-th diagonal element of the H matrix. 
*/
/*     HCOL, GC, GD, S and W will be used for working space. */

/*    The step D is calculated in a way that attempts to maximize the modu
lus*/
/*    of LFUNC(XOPT+D), subject to the bound ||D|| .LE. DELTA, where LFUNC
 is*/
/*     the KNEW-th Lagrange function. */

/*     Set some constants. */

    /* Parameter adjustments */
    zmat_dim1 = *npt;
    zmat_offset = zmat_dim1 + 1;
    zmat -= zmat_offset;
    xpt_dim1 = *npt;
    xpt_offset = xpt_dim1 + 1;
    xpt -= xpt_offset;
    --xopt;
    bmat_dim1 = *ndim;
    bmat_offset = bmat_dim1 + 1;
    bmat -= bmat_offset;
    --d__;
    --hcol;
    --gc;
    --gd;
    --s;
    --w;

    /* Function Body */
    half = .5;
    one = 1.;
    zero = 0.;
    twopi = atan(one) * 8.;
    delsq = *delta * *delta;
    nptm = *npt - *n - 1;

/*     Set the first NPT components of HCOL to the leading elements of the
 */
/*     KNEW-th column of H. */

    iterc = 0;
    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
/* L10: */
	hcol[k] = zero;
    }
    i__1 = nptm;
    for (j = 1; j <= i__1; ++j) {
	temp = zmat[*knew + j * zmat_dim1];
	if (j < *idz) {
	    temp = -temp;
	}
	i__2 = *npt;
	for (k = 1; k <= i__2; ++k) {
/* L20: */
	    hcol[k] += temp * zmat[k + j * zmat_dim1];
	}
    }
    *alpha = hcol[*knew];

/*     Set the unscaled initial direction D. Form the gradient of LFUNC at
 */
/*     XOPT, and multiply D by the second derivative matrix of LFUNC. */

    dd = zero;
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
	d__[i__] = xpt[*knew + i__ * xpt_dim1] - xopt[i__];
	gc[i__] = bmat[*knew + i__ * bmat_dim1];
	gd[i__] = zero;
/* L30: */
/* Computing 2nd power */
	d__1 = d__[i__];
	dd += d__1 * d__1;
    }
    i__2 = *npt;
    for (k = 1; k <= i__2; ++k) {
	temp = zero;
	sum = zero;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    temp += xpt[k + j * xpt_dim1] * xopt[j];
/* L40: */
	    sum += xpt[k + j * xpt_dim1] * d__[j];
	}
	temp = hcol[k] * temp;
	sum = hcol[k] * sum;
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    gc[i__] += temp * xpt[k + i__ * xpt_dim1];
/* L50: */
	    gd[i__] += sum * xpt[k + i__ * xpt_dim1];
	}
    }

/*     Scale D and GD, with a sign change if required. Set S to another */
/*     vector in the initial two dimensional subspace. */

    gg = zero;
    sp = zero;
    dhd = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* Computing 2nd power */
	d__1 = gc[i__];
	gg += d__1 * d__1;
	sp += d__[i__] * gc[i__];
/* L60: */
	dhd += d__[i__] * gd[i__];
    }
    scale = *delta / sqrt(dd);
    if (sp * dhd < zero) {
	scale = -scale;
    }
    temp = zero;
    if (sp * sp > dd * .99 * gg) {
	temp = one;
    }
    tau = scale * (abs(sp) + half * scale * abs(dhd));
    if (gg * delsq < tau * .01 * tau) {
	temp = one;
    }
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	d__[i__] = scale * d__[i__];
	gd[i__] = scale * gd[i__];
/* L70: */
	s[i__] = gc[i__] + temp * gd[i__];
    }

/*     Begin the iteration by overwriting S with a vector that has the */
/*     required length and direction, except that termination occurs if */
/*     the given D and S are nearly parallel. */

L80:
    ++iterc;
    dd = zero;
    sp = zero;
    ss = zero;
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* Computing 2nd power */
	d__1 = d__[i__];
	dd += d__1 * d__1;
	sp += d__[i__] * s[i__];
/* L90: */
/* Computing 2nd power */
	d__1 = s[i__];
	ss += d__1 * d__1;
    }
    temp = dd * ss - sp * sp;
    if (temp <= dd * 1e-8 * ss) {
	goto L160;
    }
    denom = sqrt(temp);
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	s[i__] = (dd * s[i__] - sp * d__[i__]) / denom;
/* L100: */
	w[i__] = zero;
    }

/*     Calculate the coefficients of the objective function on the circle,
 */
/*    beginning with the multiplication of S by the second derivative matr
ix.*/

    i__1 = *npt;
    for (k = 1; k <= i__1; ++k) {
	sum = zero;
	i__2 = *n;
	for (j = 1; j <= i__2; ++j) {
/* L110: */
	    sum += xpt[k + j * xpt_dim1] * s[j];
	}
	sum = hcol[k] * sum;
	i__2 = *n;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* L120: */
	    w[i__] += sum * xpt[k + i__ * xpt_dim1];
	}
    }
    cf1 = zero;
    cf2 = zero;
    cf3 = zero;
    cf4 = zero;
    cf5 = zero;
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
	cf1 += s[i__] * w[i__];
	cf2 += d__[i__] * gc[i__];
	cf3 += s[i__] * gc[i__];
	cf4 += d__[i__] * gd[i__];
/* L130: */
	cf5 += s[i__] * gd[i__];
    }
    cf1 = half * cf1;
    cf4 = half * cf4 - cf1;

/*     Seek the value of the angle that maximizes the modulus of TAU. */

    taubeg = cf1 + cf2 + cf4;
    taumax = taubeg;
    tauold = taubeg;
    isave = 0;
    iu = 49;
    temp = twopi / (doublereal) (iu + 1);
    i__2 = iu;
    for (i__ = 1; i__ <= i__2; ++i__) {
	angle = (doublereal) i__ * temp;
	cth = cos(angle);
	sth = sin(angle);
	tau = cf1 + (cf2 + cf4 * cth) * cth + (cf3 + cf5 * cth) * sth;
	if (abs(tau) > abs(taumax)) {
	    taumax = tau;
	    isave = i__;
	    tempa = tauold;
	} else if (i__ == isave + 1) {
	    tempb = tau;
	}
/* L140: */
	tauold = tau;
    }
    if (isave == 0) {
	tempa = tau;
    }
    if (isave == iu) {
	tempb = taubeg;
    }
    step = zero;
    if (tempa != tempb) {
	tempa -= taumax;
	tempb -= taumax;
	step = half * (tempa - tempb) / (tempa + tempb);
    }
    angle = temp * ((doublereal) isave + step);

/*     Calculate the new D and GD. Then test for convergence. */

    cth = cos(angle);
    sth = sin(angle);
    tau = cf1 + (cf2 + cf4 * cth) * cth + (cf3 + cf5 * cth) * sth;
    i__2 = *n;
    for (i__ = 1; i__ <= i__2; ++i__) {
	d__[i__] = cth * d__[i__] + sth * s[i__];
	gd[i__] = cth * gd[i__] + sth * w[i__];
/* L150: */
	s[i__] = gc[i__] + gd[i__];
    }
    if (abs(tau) <= abs(taubeg) * 1.1) {
	goto L160;
    }
    if (iterc < *n) {
	goto L80;
    }
L160:
    return 0;
} /* biglag_ */



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