void dlinmin(float p[], float xi[], int n, float *fret, float (*func)(float []),
void (*dfunc)(float [], float []))
{
float dbrent(float ax, float bx, float cx,
float (*f)(float), float (*df)(float), float tol, float *xmin);
float f1dim(float x);
float df1dim(float x);
void mnbrak(float *ax, float *bx, float *cx, float *fa, float *fb,
float *fc, float (*func)(float));
int j;
float xx,xmin,fx,fb,fa,bx,ax;
ncom=n;
pcom=vector(1,n);
xicom=vector(1,n);
nrfunc=func;
nrdfun=dfunc;
for (j=1;j<=n;j++) {
pcom[j]=p[j];
xicom[j]=xi[j];
}
ax=0.0;
xx=1.0;
mnbrak(&ax,&xx,&bx,&fa,&fx,&fb,f1dim);
*fret=dbrent(ax,xx,bx,f1dim,df1dim,TOL,&xmin);
for (j=1;j<=n;j++) {
xi[j] *= xmin;
p[j] += xi[j];
}
free_vector(xicom,1,n);
free_vector(pcom,1,n);
}
int main(void)
{
int i,iflag,j,nmin=0;
float ax,bx,cx,fa,fb,fc,xmin,dbr,amin[21];
printf("\nMinima of the function bessj0\n");
printf("%10s %8s %16s %12s %11s\n",
"min. #","x","bessj0(x)","bessj1(x)","DBRENT");
for (i=1;i<=100;i++) {
ax=i;
bx=i+1.0;
mnbrak(&ax,&bx,&cx,&fa,&fb,&fc,func);
dbr=dbrent(ax,bx,cx,func,dfunc,TOL,&xmin);
if (nmin == 0) {
amin[1]=xmin;
nmin=1;
printf("%7d %15.6f %12.6f %12.6f %12.6f\n",
nmin,xmin,func(xmin),dfunc(xmin),dbr);
} else {
iflag=0;
for (j=1;j<=nmin;j++)
if (fabs(xmin-amin[j]) <= EQL*xmin) iflag=1;
if (iflag == 0) {
amin[++nmin]=xmin;
printf("%7d %15.6f %12.6f %12.6f %12.6f\n",
nmin,xmin,func(xmin),dfunc(xmin),dbr);
}
}
}
return 0;
}
const MDOUBLE likeDist2Codon::giveDistanceBrent( const countTableComponentGam& ctc,
MDOUBLE& resL,
const MDOUBLE initialGuess) const {
const MDOUBLE ax=0,bx=initialGuess,cx=_maxPairwiseDistance,tol=_toll;
MDOUBLE dist=-1.0;
resL = -dbrent(ax,bx,cx,
C_evalLikeDist2Codon(ctc,_spVec),
C_evalLikeDist_d_2Codon(ctc,_spVec),
tol,
&dist);
return dist;
}
void CostFunction::dlinmin(real* &p, real* &xi, real &fret)
{
const real TOL=2.0e-8;
int j;
real xx,xmin,fx,fb,fa,bx,ax;
// Fill the temporary state vector
for (j=0; j<nState; j++) {
tempState[j] = p[j];
tempGradient[j] = xi[j];
}
ax = 0.0;
xx = 1.0;
xmin = 0.0;
mnbrack(ax,xx,bx,fa,fx,fb);
fret = dbrent(ax,xx,bx,TOL,xmin);
for (j=0; j<nState; j++) {
xi[j] *= xmin;
p[j] += xi[j];
}
}
