Пример #1
0
 int lnsrlb(integer *n, double *l, double *u, 
	integer *nbd, double *x, double *f, double *fold, 
	double *gd, double *gdold, double *g, double *d__, 
	double *r__, double *t, double *z__, double *stp, 
	double *dnorm, double *dtd, double *xstep, double *
	stpmx, integer *iter, integer *ifun, integer *iback, integer *nfgv, 
	integer *info, integer *task, logical *boxed, logical *cnstnd, integer *
	csave, integer *isave, double *dsave) /* ftnlen task_len, ftnlen 
	csave_len) */
{
    /*
    ********** 

    Subroutine lnsrlb 

    This subroutine calls subroutine dcsrch from the Minpack2 library 
      to perform the line search.  Subroutine dscrch is safeguarded so 
      that all trial points lie within the feasible region. 

    Subprograms called: 

      Minpack2 Library ... dcsrch. 

      Linpack ... dtrsl, ddot. 


                          *  *  * 

    NEOS, November 1994. (Latest revision June 1996.) 
    Optimization Technology Center. 
    Argonne National Laboratory and Northwestern University. 
    Written by 
                       Ciyou Zhu 
    in collaboration with R.H. Byrd, P. Lu-Chen and J. Nocedal. 


    ********** 
    */


    /* Table of constant values */
    static double c_b14 = FTOL;
    static double c_b15 = GTOL;
    static double c_b16 = XTOL;
    static double c_b17 = STEPMIN;
    /* System generated locals */
    integer i__1;
    double d__1;


    /* Local variables */
    static integer i__;
    static double a1, a2;

    /* Parameter adjustments */
    --z__;
    --t;
    --r__;
    --d__;
    --g;
    --x;
    --nbd;
    --u;
    --l;
    --isave;
    --dsave;

    /* Function Body */
    if ( *task == FG_LN ) { 
        goto L556;
    }
    *dtd = ddot(n, &d__[1], &c__1, &d__[1], &c__1);
    *dnorm = sqrt(*dtd);
    /*     Determine the maximum step length. */
    *stpmx = 1e10;
    if (*cnstnd) {
        if (*iter == 0) {
            *stpmx = 1.;
        } else {
            i__1 = *n;
            for (i__ = 1; i__ <= i__1; ++i__) {
                a1 = d__[i__];
                if (nbd[i__] != 0) {
                    if (a1 < 0. && nbd[i__] <= 2) {
                        a2 = l[i__] - x[i__];
                        if (a2 >= 0.) {
                            *stpmx = 0.;
                        } else if (a1 * *stpmx < a2) {
                            *stpmx = a2 / a1;
                        }
                    } else if (a1 > 0. && nbd[i__] >= 2) {
                        a2 = u[i__] - x[i__];
                        if (a2 <= 0.) {
                            *stpmx = 0.;
                        } else if (a1 * *stpmx > a2) {
                            *stpmx = a2 / a1;
                        }
                    }
                }
                /* L43: */
            }
        }
    }
    if (*iter == 0 && ! (*boxed)) {
        /* Computing MIN */
        d__1 = 1. / *dnorm;
        *stp = min(d__1,*stpmx);
    } else {
        *stp = 1.;
    }
    dcopy(n, &x[1], &c__1, &t[1], &c__1);
    dcopy(n, &g[1], &c__1, &r__[1], &c__1);
    *fold = *f;
    *ifun = 0;
    *iback = 0;
    *csave = START;
L556:
    *gd = ddot(n, &g[1], &c__1, &d__[1], &c__1);
    if (*ifun == 0) {
        *gdold = *gd;
        if (*gd >= 0.) {
            /*  the directional derivative >=0. */
            /*  Line search is impossible. */
            /*
             * printf("ascend direction in projection gd = %.2e\n", *gd );
             * */
            *info = -4;
            return 0;
        }
    }
    dcsrch(f, gd, stp, &c_b14, &c_b15, &c_b16, &c_b17, stpmx, csave, &isave[
            1], &dsave[1]);/* (ftnlen)60);*/
    *xstep = *stp * *dnorm;
    if (  !(IS_WARNING(*csave)) && !(IS_CONVERGED(*csave)) )  {
/*     if (     !( (csave>=WARNING)&&(csave<=WARNING_END) )   &&   */
/*              !( (csave>=CONVERGENCE)&&(csave<=CONVERGENCE_END) )   ) { */
/*     if (s_cmp(csave, "CONV", (ftnlen)4, (ftnlen)4) != 0 && s_cmp(csave, "WARN" */
/*                 , (ftnlen)4, (ftnlen)4) != 0) { */
        *task = FG_LNSRCH;
        ++(*ifun);
        ++(*nfgv);
        *iback = *ifun - 1;
        if (*stp == 1.) {
            dcopy(n, &z__[1], &c__1, &x[1], &c__1);
        } else {
            i__1 = *n;
            for (i__ = 1; i__ <= i__1; ++i__) {
                x[i__] = *stp * d__[i__] + t[i__];
                /* L41: */
            }
        }
    } else {
        *task = NEW_X;
    }
    return 0;
} /* lnsrlb */
Пример #2
0
/**
 * Maximum full pseudolikelihood method to estimate parameters.
 *
 * Minimization done by gradient L-BFGS with wolfe
 *
 * @param [in] p Number of variables
 * @param [in,out] mu pdim Real vector. Mu parameter of the mv-vm dist
 * @param [in,out] kappa pdim Real vector. Kappa parameter of the mv-vm dist
 * @param [in,out] lambda pxp Real matrix on row-leading order. Lambda parameter of the mv-vm dist
 * @param [in] n Number of samples
 * @param [in] samples
 * @param [in] phi Prior matrix
 * @param [in] H Confidence matrix
 * @param [in] verbose
 * @param [in] prec
 * @param [in] tol 
 * @param [in] mprec
 * @param [in] lower
 * @param [in] upper
 * @param [in] bounded
 *
 * @returns Natural logarithm of the pseudolikelihood of the fitted distribution (aprox)
 */
double mvvonmises_lbfgs_fit(int p, double* mu, double* kappa, double* lambda, int n, double *samples, double* phi, double *H,
                            int verbose, double prec, double tol, int mprec, double *lower, double *upper, int *bounded ){

    uint_fast16_t i,j,k;

    /* Von Mises computation parameters*/
    long double *S,*C,*ro;
    double *d_kappa,*d_lambda;

    S = malloc(sizeof(long double)*n*p*3);
    C = S + (n*p);
    ro = C + (n*p);

    /* Set up instance */
    multiCircularMean(n,p,samples,mu);

    // Do the theta transformation
    mv_theta_cos_sinTransform(n,p,samples,mu,S,C);

    /* Derivatives */
    d_kappa = malloc(sizeof(double)*(p+(p*p)));
    d_lambda = d_kappa + p;

#ifdef DEBUG
    double *d_kappa_fd,*d_lambda_fd;

    d_kappa_fd = malloc(sizeof(double)*(p+(p*p)));
    d_lambda_fd = d_kappa_fd + p;
#endif


    /* LBFGS variables */
    /* integer and logical types come from lbfgsb.h */
    integer iprint = verbose; // No output
    double  factr = prec; // Moderate prec
    double  pgtol = tol; // Gradient tolerance
    integer m = mprec;       // Number of corrections

    /* Fixd workspaces */
    integer taskValue;
    integer *task = &taskValue;
    integer csaveValue;
    integer *csave = &csaveValue;
    integer isave[44];
    double  dsave[29];
    logical lsave[4];

    /* Dynamic parameters (Given, but we might have to cast)*/
    integer nvar = ((p*p)-p)/2 + p;  // Number of variables

    double  f = DBL_MAX;   // Eval value
    double *g = calloc(sizeof(double),nvar*4); // Gradient value
    double *l = g+nvar; // lower bounds
    double *u = l+nvar; // upper bounds
    double *x = u+nvar; // Point value
    integer *nbd = calloc(sizeof(integer),nvar);

    /* Dynamic Workspaces*/
    double  *wa  = calloc(sizeof(double),( (2*m + 5)*nvar + 11 * m * m + 8 * m));
    integer *iwa = calloc(sizeof(integer) , 3 * nvar );

    /* Copy parameters (this way so casting is done)*/
    for(i=0;i<nvar; i++){
        l[i]   = lower[i] ;
        u[i]   = upper[i];
        nbd[i] = bounded[i];
    }


    /* Copy initial values to X*/
    // Kappa values
    for(i=0;i<p;i++){
        x[i] = kappa[i];
    }

    // Lambda values
    for(i=0, k=0; i < (p-1) ; i++) {
        for( j=(i+1) ; j < p ; j++, k++){
            x[p+k] = lambda[ i*p + j];
        }
    }

    /* Set task to START*/
    *task = (integer)START;

    do{
        setulb(&nvar,&m,x,l,u,nbd,&f,g,&factr,&pgtol,wa,iwa,task,&iprint,csave,lsave,isave,dsave);

        // If F and G comp. is requiered
        if( IS_FG(*task) ){

            // Copy kappa
            memcpy(kappa,x,sizeof(double)*p);

            // Copy lambda
            matrixUpperToFull(p,x+p,lambda);

            // Call loss function with current x
            f = mv_vonmises_lossFunction(n,p,kappa,lambda,S,C,ro,d_kappa,d_lambda);
/*******************************************************/
#ifdef DEBUG
            // Approx DF for kappa
            for(i=0;i<p;i++){
                kappa[i]+=1E-9;
                d_kappa_fd[i] = (mv_vonmises_lossFunction(n,p,kappa,lambda,S,C,ro,NULL,NULL)-f)/1E-9  ;
                kappa[i]-=1E-9;
                printf("KAPPA(%d):  calc %f \t  fd approx: %f \t DIFF: %f \n",i,d_kappa[i],d_kappa_fd[i],fabs(d_kappa[i]-d_kappa_fd[i]));
            }

            // Approx DF for lambda
            for(i=0;i<(p-1);i++){
                    for(j=i+1;j<p;j++){
                        lambda[i*p + j] += 1E-9 ; 
                        lambda[j*p + i] += 1E-9 ; 
                        d_lambda_fd[i*p + j] = (mv_vonmises_lossFunction(n,p,kappa,lambda,S,C,ro,NULL,NULL)-f)/1E-9  ;
                        d_lambda_fd[j*p + i] = d_lambda_fd[i*p + j];
                        printf("Lambda(%d,%d):  calc %f \t  fd approx: %f \t DIFF: %f \n",i,j,d_lambda[i*p + j],d_lambda_fd[i*p +j],fabs(d_lambda[i*p +j ]-d_lambda_fd[i*p + j]));
                        lambda[i*p + j] -= 1E-9 ; 
                        lambda[j*p + i] -= 1E-9 ; 
                    }
            }

#endif
/**************************************************************/

            // Kappa partials
            memcpy(g,d_kappa,sizeof(double)*p);

            // Apply penalization
            if( (phi!=NULL) && (H != NULL) ){

                double fnorm = 0;
                double fnorm_term;

                // Compute f norm
                 for (i=0; i < (p-1); i++) {
                    for (j=i+1; j < p; j++){
                        // RECALL: P is actually diag(kappa) - lambda
                        fnorm_term = (-lambda[ i*p + j] - phi[ i*p + j]) * H[ i*p + j];
                        fnorm += fnorm_term * fnorm_term;
                    }
                 }
            
                 // We also need to include kappa
                 for (i=0; i<p; i++){
                        fnorm_term = (kappa[ i ] - phi[ i*p + i]) * H[ i*p + i];
                        fnorm += fnorm_term * fnorm_term;
                 }
                 // Add norm to F
                 fnorm = sqrtl(fnorm);
                 //f += log(n)*fnorm; // What is this logn doing here???
                 f += fnorm;
#ifdef DEBUG
                printf("MATRIX P:\n");
                for(i=0; i<p ; i++){
                    for(j = 0 ; j<p ; j++){
                        if( j == i ) printf( "%f\t", kappa[j]);
                        else printf( "%f\t", -lambda[i*p + j]);
                    }
                    printf("\n");
                }
                
                printf("MATRIX Phi:\n");
                for(i=0; i<p ; i++){
                    for(j = 0 ; j<p ; j++){
                        printf( "%f\t", phi[i*p + j]);
                    }
                    printf("\n");
                }
                printf("MATRIX H:\n");
                for(i=0; i<p ; i++){
                    for(j = 0 ; j<p ; j++){
                        printf( "%f\t", H[i*p + j]);
                    }
                    printf("\n");
                }
                printf("FNORM: %f\n", fnorm);

#endif
                if(fnorm != 0){
                    // Modify lambda partials
                    for (i=0; i < (p-1); i++) {
                        for (j=i+1; j < p; j++){
                            // RECALL: P is actually diag(kappa) - lambda
                            // d_lambda[i*p + j] += log(n) * (-H[i*p + j] * H[i*p + j] * ( (-lambda[i*p + j]) - phi[ i*p + j] ) / fnorm) ;
                            d_lambda[i*p + j] += (-H[i*p + j] * H[i*p + j] * ( (-lambda[i*p + j]) - phi[ i*p + j] ) / fnorm) ;
                            d_lambda[j*p + i] = d_lambda[i*p + j];
                        }
                    }
    
                    // Modify kappa partials
                    for (i=0; i<p; i++){
                            //d_kappa[i]+= log(n) * H[i*p + i] * H[i*p + i] * ( kappa[i] - phi[ i*p + i] ) / fnorm ;
                            d_kappa[i]+= H[i*p + i] * H[i*p + i] * ( kappa[i] - phi[ i*p + i] ) / fnorm ;
                     }
                }
            }

            // Lambda partials (to vector)
            for(i=0, k=0; i < (p-1) ; i++) {
                for( j=(i+1) ; j < p ; j++, k++){
                    g[p+k] = d_lambda[ i*p + j];
                }
            }
        }

        // Additional stopping criteria to avoid infinite looping

        else if( *task == NEW_X ){

            /* Control number of iterations */
            if(isave[33] >= 100 ){
                *task = STOP_ITER;
            }
            /* Terminate if |proj g| / (1+|f|) < 1E-10 */
            else if ( dsave[12] <= (fabs(f) + 1) * 1E-10 ){
                *task = STOP_GRAD;
            }
        }

    }while( IS_FG(*task) || *task==NEW_X);


    /* Copy back x */
    for(i=0;i<p;i++) kappa[i]=x[i];
    matrixUpperToFull(p,x+p,lambda);

    /** FreE*/

#ifdef DEBUG
            free(d_kappa_fd);
#endif
    free(S); free(d_kappa); free(g);
    free(wa); free(iwa); free(nbd);

    if( IS_ERROR(*task) || IS_WARNING(*task) )
        return NAN;
    else
        return (double)f;
}
Пример #3
0
/* ======================= The end of lnsrlb ============================= */
int dcsrch(double *f, double *g, double *stp, 
        double *ftol, double *gtol, double *xtol, double *
        stpmin, double *stpmax, integer *task, integer *isave, double *
        dsave) /* ftnlen task_len) */
{
    /* System generated locals */
    double d__1;


    /* Local variables */
    static double fm, gm, fx, fy, gx, gy, fxm, fym, gxm, gym, stx, sty;
    static integer stage;
    static double finit, ginit, width, ftest, gtest, stmin, stmax, width1;
    static logical brackt;

    /*
     ********** 

     Subroutine dcsrch 

     This subroutine finds a step that satisfies a sufficient 
     decrease condition and a curvature condition. 

     Each call of the subroutine updates an interval with 
     endpoints stx and sty. The interval is initially chosen 
     so that it contains a minimizer of the modified function 

     psi(stp) = f(stp) - f(0) - ftol*stp*f'(0). 

     If psi(stp) <= 0 and f'(stp) >= 0 for some step, then the 
     interval is chosen so that it contains a minimizer of f. 

     The algorithm is designed to find a step that satisfies 
     the sufficient decrease condition 

     f(stp) <= f(0) + ftol*stp*f'(0), 

     and the curvature condition 

     abs(f'(stp)) <= gtol*abs(f'(0)). 

     If ftol is less than gtol and if, for example, the function 
     is bounded below, then there is always a step which satisfies 
     both conditions. 

     If no step can be found that satisfies both conditions, then 
     the algorithm stops with a warning. In this case stp only 
     satisfies the sufficient decrease condition. 

     A typical invocation of dcsrch has the following outline: 

     task = 'START' 
     10 continue 
     call dcsrch( ... ) 
     if (task .eq. 'FG') then 
     Evaluate the function and the gradient at stp 
     goto 10 
     end if 

NOTE: The user must no alter work arrays between calls. 

The subroutine statement is 

subroutine dcsrch(f,g,stp,ftol,gtol,xtol,stpmin,stpmax, 
task,isave,dsave) 
where 

f is a double precision variable. 
On initial entry f is the value of the function at 0. 
On subsequent entries f is the value of the 
function at stp. 
On exit f is the value of the function at stp. 

g is a double precision variable. 
On initial entry g is the derivative of the function at 0. 
On subsequent entries g is the derivative of the 
function at stp. 
On exit g is the derivative of the function at stp. 

stp is a double precision variable. 
On entry stp is the current estimate of a satisfactory 
step. On initial entry, a positive initial estimate 
must be provided. 
On exit stp is the current estimate of a satisfactory step 
if task = 'FG'. If task = 'CONV' then stp satisfies 
the sufficient decrease and curvature condition. 

    ftol is a double precision variable. 
        On entry ftol specifies a nonnegative tolerance for the 
        sufficient decrease condition. 
        On exit ftol is unchanged. 

        gtol is a double precision variable. 
        On entry gtol specifies a nonnegative tolerance for the 
        curvature condition. 
        On exit gtol is unchanged. 

        xtol is a double precision variable. 
        On entry xtol specifies a nonnegative relative tolerance 
        for an acceptable step. The subroutine exits with a 
            warning if the relative difference between sty and stx 
                is less than xtol. 
                On exit xtol is unchanged. 

                stpmin is a double precision variable. 
                On entry stpmin is a nonnegative lower bound for the step. 
                On exit stpmin is unchanged. 

                stpmax is a double precision variable. 
                On entry stpmax is a nonnegative upper bound for the step. 
                On exit stpmax is unchanged. 

                task is a character variable of length at least 60. 
                On initial entry task must be set to 'START'. 
                On exit task indicates the required action: 

                If task(1:2) = 'FG' then evaluate the function and 
                derivative at stp and call dcsrch again. 

                If task(1:4) = 'CONV' then the search is successful. 

                If task(1:4) = 'WARN' then the subroutine is not able 
                to satisfy the convergence conditions. The exit value of 
                stp contains the best point found during the search. 

                If task(1:5) = 'ERROR' then there is an error in the 
                input arguments. 

                On exit with convergence, a warning or an error, the 
                variable task contains additional information. 

                isave is an integer work array of dimension 2. 

                dsave is a double precision work array of dimension 13. 

                Subprograms called 

                MINPACK-2 ... dcstep 

                MINPACK-1 Project. June 1983. 
                Argonne National Laboratory. 
                Jorge J. More' and David J. Thuente. 

                MINPACK-2 Project. October 1993. 
                Argonne National Laboratory and University of Minnesota. 
                Brett M. Averick, Richard G. Carter, and Jorge J. More'. 

                ********** 
                */
                /*     Initialization block. */
                /* Parameter adjustments */
                --dsave;
    --isave;

    /* Function Body */
    if ( *task == START ) {
        /*        Check the input arguments for errors.  See lbfgsb.h for messages */
        if (*stp < *stpmin)  *task=ERROR_SMALLSTP;
        if (*stp > *stpmax)  *task=ERROR_LARGESTP;
        if (*g >= 0.)        *task=ERROR_INITIAL;
        if (*ftol < 0.)      *task=ERROR_FTOL;
        if (*gtol < 0.)      *task=ERROR_GTOL;
        if (*xtol < 0.)      *task=ERROR_XTOL;
        if (*stpmin < 0.)    *task=ERROR_STP0;
        if (*stpmax < *stpmin) *task=ERROR_STP1;
        /*        Exit if there are errors on input. */
        if ( IS_ERROR(*task) ) {
            return 0;
        }
        /*        Initialize local variables. */
        brackt = FALSE_;
        stage = 1;
        finit = *f;
        ginit = *g;
        gtest = *ftol * ginit;
        width = *stpmax - *stpmin;
        width1 = width / .5;
        /*        The variables stx, fx, gx contain the values of the step, */
        /*        function, and derivative at the best step. */
        /*        The variables sty, fy, gy contain the value of the step, */
        /*        function, and derivative at sty. */
        /*        The variables stp, f, g contain the values of the step, */
        /*        function, and derivative at stp. */
        stx = 0.;
        fx = finit;
        gx = ginit;
        sty = 0.;
        fy = finit;
        gy = ginit;
        stmin = 0.;
        stmax = *stp + *stp * 4.;
/*         s_copy(task, "FG", task_len, (ftnlen)2); */
        *task = FG;
        goto L1000;
    } else {
        /*        Restore local variables. */
        if (isave[1] == 1) {
            brackt = TRUE_;
        } else {
            brackt = FALSE_;
        }
        stage = isave[2];
        ginit = dsave[1];
        gtest = dsave[2];
        gx = dsave[3];
        gy = dsave[4];
        finit = dsave[5];
        fx = dsave[6];
        fy = dsave[7];
        stx = dsave[8];
        sty = dsave[9];
        stmin = dsave[10];
        stmax = dsave[11];
        width = dsave[12];
        width1 = dsave[13];
    }
    /*     If psi(stp) <= 0 and f'(stp) >= 0 for some step, then the */
    /*     algorithm enters the second stage. */
    ftest = finit + *stp * gtest;
    if (stage == 1 && *f <= ftest && *g >= 0.) {
        stage = 2;
    }
    /*     Test for warnings. */
    if (brackt && (*stp <= stmin || *stp >= stmax)) {
        *task = WARNING_ROUND;
    }
    if (brackt && stmax - stmin <= *xtol * stmax) {
        *task = WARNING_XTOL;
    }
    if (*stp == *stpmax && *f <= ftest && *g <= gtest) {
        *task = WARNING_STPMAX;
    }
    if (*stp == *stpmin && (*f > ftest || *g >= gtest)) {
        *task = WARNING_STPMIN;
    }
    /*     Test for convergence. */
    if (*f <= ftest && abs(*g) <= *gtol * (-ginit)) {
        *task = CONVERGENCE;
    }
    /*     Test for termination. */
/*     if (     ( (task>=WARNING)&&(task<=WARNING_END) )    || */
/*              ( (task>=CONVERGENCE)&&(task<=CONVERGENCE_END) )   ) { */
    if ( (IS_WARNING(*task)) || (IS_CONVERGED(*task) ) ) {
        goto L1000;
    }
    /*     A modified function is used to predict the step during the */
    /*     first stage if a lower function value has been obtained but */
    /*     the decrease is not sufficient. */
    if (stage == 1 && *f <= fx && *f > ftest) {
        /*        Define the modified function and derivative values. */
        fm = *f - *stp * gtest;
        fxm = fx - stx * gtest;
        fym = fy - sty * gtest;
        gm = *g - gtest;
        gxm = gx - gtest;
        gym = gy - gtest;
        /*        Call dcstep to update stx, sty, and to compute the new step. */
        dcstep(&stx, &fxm, &gxm, &sty, &fym, &gym, stp, &fm, &gm, &brackt, &
                stmin, &stmax);
        /*        Reset the function and derivative values for f. */
        fx = fxm + stx * gtest;
        fy = fym + sty * gtest;
        gx = gxm + gtest;
        gy = gym + gtest;
    } else {
        /*       Call dcstep to update stx, sty, and to compute the new step. */
        dcstep(&stx, &fx, &gx, &sty, &fy, &gy, stp, f, g, &brackt, &stmin, &
                stmax);
    }
    /*     Decide if a bisection step is needed. */
    if (brackt) {
        if ((d__1 = sty - stx, abs(d__1)) >= width1 * .66) {
            *stp = stx + (sty - stx) * .5;
        }
        width1 = width;
        width = (d__1 = sty - stx, abs(d__1));
    }
    /*     Set the minimum and maximum steps allowed for stp. */
    if (brackt) {
        stmin = min(stx,sty);
        stmax = max(stx,sty);
    } else {
        stmin = *stp + (*stp - stx) * 1.1;
        stmax = *stp + (*stp - stx) * 4.;
    }
    /*     Force the step to be within the bounds stpmax and stpmin. */
    *stp = max(*stp,*stpmin);
    *stp = min(*stp,*stpmax);
    /*     If further progress is not possible, let stp be the best */
    /*     point obtained during the search. */
    /*     if (brackt && (*stp <= stmin || *stp >= stmax) || brackt && stmax - stmin  */
    /* SRB: guess the precedence. && precedence over || */
    if ( (brackt && (*stp <= stmin || *stp >= stmax) ) || (brackt && stmax - stmin 
                <= *xtol * stmax)) {
        *stp = stx;
    }
    /*     Obtain another function and derivative. */
/*     s_copy(task, "FG", task_len, (ftnlen)2); */
    *task = FG;
L1000:
    /*     Save local variables. */
    if (brackt) {
        isave[1] = 1;
    } else {
        isave[1] = 0;
    }
    isave[2] = stage;
    dsave[1] = ginit;
    dsave[2] = gtest;
    dsave[3] = gx;
    dsave[4] = gy;
    dsave[5] = finit;
    dsave[6] = fx;
    dsave[7] = fy;
    dsave[8] = stx;
    dsave[9] = sty;
    dsave[10] = stmin;
    dsave[11] = stmax;
    dsave[12] = width;
    dsave[13] = width1;
    return 0;
} /* dcsrch */