smpl_t
aubio_beattracking_get_confidence (aubio_beattracking_t * bt)
{
if (bt->gp) {
return fvec_max (bt->acfout) / fvec_sum(bt->acfout);
} else {
return 0.;
}
}
smpl_t
aubio_beattracking_get_confidence (const aubio_beattracking_t * bt)
{
if (bt->gp) {
smpl_t acf_sum = fvec_sum(bt->acfout);
if (acf_sum != 0.) {
return fvec_quadratic_peak_mag (bt->acfout, bt->gp) / acf_sum;
}
}
return 0.;
}
double nn_thread (int npt, int nclust, int d,
const float *codebook, const float *coords,
int *vw, int n_thread)
{
float *vwdis2=fvec_new(npt);
knn_full_thread (2, npt, nclust, d, 1, codebook, coords, NULL, vw, vwdis2, n_thread);
double toterr = fvec_sum(vwdis2, npt);
free(vwdis2);
return toterr;
}
double nn (int npt, int nclust, int d,
const float *codebook, const float *coords, int *vw)
{
/* The distances to centroids that will be returned */
float *vwdis = fvec_new(npt);
knn_full (2, npt, nclust, d, 1, codebook, coords, NULL, vw, vwdis);
double toterr = fvec_sum(vwdis, npt);
free(vwdis);
return toterr;
}
gmm_t * gmm_learn (int di, int ni, int ki, int niter,
const float * v, int nt, int seed, int nredo,
int flags)
{
long d=di,k=ki,n=ni;
int iter, iter_tot = 0;
double old_key, key = 666;
niter = (niter == 0 ? 10000 : niter);
/* the GMM parameters */
float * p = fvec_new_0 (n * k); /* p(ci|x) for all i */
gmm_t * g = gmm_new (d, k);
/* initialize the GMM: k-means + variance estimation */
int * nassign = ivec_new (n); /* not useful -> to be removed when debugged */
float * dis = fvec_new (n);
kmeans (d, n, k, niter, v, nt, seed, nredo, g->mu, dis, NULL, nassign);
fflush (stderr);
fprintf (stderr, "assign = ");
ivec_print (nassign, k);
fprintf (stderr, "\n");
free (nassign);
/* initialization of the GMM parameters assuming a diagonal matrix */
fvec_set (g->w, k, 1.0 / k);
double sig = fvec_sum (dis, n) / n;
printf ("sigma at initialization = %.3f\n", sig);
fvec_set (g->sigma, k * d, sig);
free (dis);
/* start the EM algorithm */
fprintf (stdout, "<><><><> GMM <><><><><>\n");
if(flags & GMM_FLAGS_PURE_KMEANS) niter=0;
for (iter = 1 ; iter <= niter ; iter++) {
gmm_compute_p_thread (n, v, g, p, flags, nt);
fflush(stdout);
gmm_handle_empty(n, v, g, p);
gmm_compute_params (n, v, p, g, flags, nt);
fflush(stdout);
iter_tot++;
/* convergence reached -> leave */
old_key = key;
key = fvec_sum (g->mu, k * d);
printf ("keys %5d: %.6f -> %.6f\n", iter, old_key, key);
fflush(stdout);
if (key == old_key)
break;
}
fprintf (stderr, "\n");
free(p);
return g;
}
/* estimate the GMM parameters */
static void gmm_compute_params (int n, const float * v, const float * p,
gmm_t * g,
int flags,
int n_thread)
{
long i, j;
long d=g->d, k=g->k;
float * vtmp = fvec_new (d);
float * mu_old = fvec_new_cpy (g->mu, k * d);
float * w_old = fvec_new_cpy (g->w, k);
fvec_0 (g->w, k);
fvec_0 (g->mu, k * d);
fvec_0 (g->sigma, k * d);
if(0) {
/* slow and simple */
for (j = 0 ; j < k ; j++) {
double dtmp = 0;
for (i = 0 ; i < n ; i++) {
/* contribution to the gaussian weight */
dtmp += p[i * k + j];
/* contribution to mu */
fvec_cpy (vtmp, v + i * d, d);
fvec_mul_by (vtmp, d, p[i * k + j]);
fvec_add (g->mu + j * d, vtmp, d);
/* contribution to the variance */
fvec_cpy (vtmp, v + i * d, d);
fvec_sub (vtmp, mu_old + j * d, d);
fvec_sqr (vtmp, d);
fvec_mul_by (vtmp, d, p[i * k + j]);
fvec_add (g->sigma + j * d, vtmp, d);
}
g->w[j] = dtmp;
}
} else {
/* fast and complicated */
if(n_thread<=1)
compute_sum_dcov(n,k,d,v,mu_old,p,g->mu,g->sigma,g->w);
else
compute_sum_dcov_thread(n,k,d,v,mu_old,p,g->mu,g->sigma,g->w,n_thread);
}
if(flags & GMM_FLAGS_1SIGMA) {
for (j = 0 ; j < k ; j++) {
float *sigma_j=g->sigma+j*d;
double var=fvec_sum(sigma_j,d)/d;
fvec_set(sigma_j,d,var);
}
}
long nz=0;
for(i=0; i<k*d; i++)
if(g->sigma[i]<min_sigma) {
g->sigma[i]=min_sigma;
nz++;
}
if(nz) printf("WARN %ld sigma diagonals are too small (set to %g)\n",nz,min_sigma);
for (j = 0 ; j < k ; j++) {
fvec_div_by (g->mu + j * d, d, g->w[j]);
fvec_div_by (g->sigma + j * d, d, g->w[j]);
}
assert(finite(fvec_sum(g->mu, k*d)));
fvec_normalize (g->w, k, 1);
printf ("w = ");
fvec_print (g->w, k);
double imfac = k * fvec_sum_sqr (g->w, k);
printf (" imfac = %.3f\n", imfac);
free (vtmp);
free (w_old);
free (mu_old);
}
