void
gen_interp(struct curve_points *plot)
{
spline_coeff *sc;
double *bc;
struct coordinate *new_points;
int i, curves;
int first_point, num_points;
curves = num_curves(plot);
new_points = gp_alloc((samples_1 + 1) * curves * sizeof(struct coordinate),
"interpolation table");
first_point = 0;
for (i = 0; i < curves; i++) {
num_points = next_curve(plot, &first_point);
switch (plot->plot_smooth) {
case SMOOTH_CSPLINES:
sc = cp_tridiag(plot, first_point, num_points);
do_cubic(plot, sc, first_point, num_points,
new_points + i * (samples_1 + 1));
free(sc);
break;
case SMOOTH_ACSPLINES:
sc = cp_approx_spline(plot, first_point, num_points);
do_cubic(plot, sc, first_point, num_points,
new_points + i * (samples_1 + 1));
free(sc);
break;
case SMOOTH_BEZIER:
case SMOOTH_SBEZIER:
bc = cp_binomial(num_points);
do_bezier(plot, bc, first_point, num_points,
new_points + i * (samples_1 + 1));
free((char *) bc);
break;
case SMOOTH_KDENSITY:
do_kdensity( plot, first_point, num_points,
new_points + i * (samples_1 + 1));
break;
default: /* keep gcc -Wall quiet */
;
}
new_points[(i + 1) * (samples_1 + 1) - 1].type = UNDEFINED;
first_point += num_points;
}
free(plot->points);
plot->points = new_points;
plot->p_max = curves * (samples_1 + 1);
plot->p_count = plot->p_max - 1;
return;
}
void bezier_interp(std::vector<T> x_in, std::vector<T> y_in,
std::vector<T> &x_out, std::vector<T> &y_out,
int fp, int np, int ns) {
/// This function interpolates with a bezier function of degree n,
/// where n is the number of datapoints.
///
/// x_in,y_in Input datapoints
/// x_out,y_out The output datapoints for Bezier function
/// fp First datapoints (default=0)
/// np Number of datapoints (default=x_in.size())
/// ns Number of samples (default=np)
if (x_in.size()!=y_in.size()) {
std::cout << "BEZIER Error: x_in & y_in have different dimensions.\n";
exit(EXIT_FAILURE);
}
if (np==-1) np=x_in.size();
if (ns==-1) ns=np;
if (np>x_in.size()-fp) {
std::cout << "BEZIER Error: number of datapoints is greater than the size of input vectors.\n";
exit(EXIT_FAILURE);
}
if (x_out.size()!=ns || y_out.size()!=ns) {
std::cout << "BEZIER Error: The dimensions of output bezier vector must be = n_samples.\n";
exit(EXIT_FAILURE);
}
double *bc = cp_binomial(np);
for (int i=0; i<ns; i++) {
double sr = (double)i/(double)(ns-1);
unsigned int n = np-1;
float px=0., py=0.;
if (sr == 0.0) {
px = x_in[fp];
py = y_in[fp];
}
else if (sr == 1.0) {
px = x_in[fp+n];
py = y_in[fp+n];
}
else {
double log_dsr_to_the_n = n*log(1-sr);
double log_sr_over_dsr = log(sr)-log(1-sr);
for (unsigned j=0; j<=n; j++) {
double u = exp(bc[j]+log_dsr_to_the_n+j*log_sr_over_dsr);
px += x_in[j+fp]*u;
py += y_in[j+fp]*u;
}
}
x_out[i]=px;
y_out[i]=py;
}
delete [] bc;
}
